Pale, stony, often shallow over solid chalk or limestone, and always alkaline. Fizzes when a little vinegar is dropped on a lump, which is the one soil test that gives a definite answer in seconds.
Not sure this is you? Four hand tests will settle it — the squeeze test alone distinguishes the main textures in about a minute.
Horticultural consensusmoderate confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
Sourced guidancemoderate confidence
Checked 2026-08-13
Applies when: Chalk soils range from a few centimetres over rock on a scarp to a deep clay-with-flints cap on a plateau. The shallow case is the one that constrains what can be grown, and is common enough to plan around.
Checked 2026-08-13
Sourced guidancemoderate confidence
Checked 2026-08-13
Every soil grows something better than loam does, and a description that lists only problems is a complaint rather than intelligence.
Sourced guidancehigh confidence
Checked 2026-08-13
Sourced guidancehigh confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
Sourced guidancehigh confidence
Checked 2026-08-13
Horticultural consensusmoderate confidence
Checked 2026-08-13
The thing most worth knowing
Chalk is the soil people most often try to change and least often can. The productive move is to grow what suits it in the ground and put the acid-lovers in pots, rather than to spend years fighting the geology.
Not problems it causes — problems whose severity this soil materially changes. The distinction matters, because the remedy is usually about the soil rather than the pest.
The defining disorder of alkaline soils. It is not a shortage of iron in the soil but an inability of the plant to take up what is there, which is why feeding iron in ordinary form does nothing and a sequestered form works temporarily.
Sourced guidancehigh confidence
Checked 2026-08-13
Computed across 223 plants by comparing each one's recorded requirements against this soil's recorded characteristics. Every verdict can be taken apart into the criteria that produced it, and a recorded horticultural fact overrides the computation where one exists.
| Plant | Why |
|---|---|
| Bay | Chalky and alkaline suits Bay as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Bearded iris | Chalky and alkaline suits Bearded iris as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Berberis | Chalky and alkaline suits Berberis as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Blue fescue | Chalky and alkaline suits Blue fescue as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Borage | Chalky and alkaline suits Borage as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Buddleja | Chalky and alkaline suits Buddleja as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Californian lilac | Chalky and alkaline suits Californian lilac as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Cotoneaster | Chalky and alkaline suits Cotoneaster as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Crocus | Chalky and alkaline suits Crocus as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Daffodil | Chalky and alkaline suits Daffodil as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Echinacea | Chalky and alkaline suits Echinacea as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Epimedium | Chalky and alkaline suits Epimedium as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Escallonia | Chalky and alkaline suits Escallonia as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Firethorn | Chalky and alkaline suits Firethorn as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Grape hyacinth | Chalky and alkaline suits Grape hyacinth as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hard shield fern | Chalky and alkaline suits Hard shield fern as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hardy cyclamen | Chalky and alkaline suits Hardy cyclamen as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hardy geranium | Chalky and alkaline suits Hardy geranium as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hawthorn | Chalky and alkaline suits Hawthorn as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hebe | Chalky and alkaline suits Hebe as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Holly | Chalky and alkaline suits Holly as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hyacinth | Chalky and alkaline suits Hyacinth as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Hyssop | Chalky and alkaline suits Hyssop as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Ivy | Chalky and alkaline suits Ivy as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Lavender | Sharp drainage and a high pH are the conditions lavender evolved on, and chalky gardens grow it better than the loam everyone else envies. The same is true of thyme, sage and oregano — the group that is difficult everywhere else is easy here.recorded fact |
| Lemon thyme | Chalky and alkaline suits Lemon thyme as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Mahonia | Chalky and alkaline suits Mahonia as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Maidenhair spleenwort | Chalky and alkaline suits Maidenhair spleenwort as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Marjoram | Chalky and alkaline suits Marjoram as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Mexican feather grass | Chalky and alkaline suits Mexican feather grass as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Mexican orange blossom | Chalky and alkaline suits Mexican orange blossom as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Miscanthus | Chalky and alkaline suits Miscanthus as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Mock orange | Chalky and alkaline suits Mock orange as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Nerine | Chalky and alkaline suits Nerine as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Oregano | Chalky and alkaline suits Oregano as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Ornamental allium | Chalky and alkaline suits Ornamental allium as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Osmanthus | Chalky and alkaline suits Osmanthus as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Periwinkle | Chalky and alkaline suits Periwinkle as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Rosemary | Sharp drainage and a high pH are the conditions rosemary evolved on, and chalky gardens grow it better than the loam everyone else is envious of. The same is true of thyme, sage and oregano — the group that is difficult everywhere else is easy here.recorded fact |
| Sage | Chalky and alkaline suits Sage as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Salad burnet | Chalky and alkaline suits Salad burnet as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Salvia | Chalky and alkaline suits Salvia as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Savory | Chalky and alkaline suits Savory as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Tarragon | Chalky and alkaline suits Tarragon as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Thyme | Chalky and alkaline suits Thyme as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Tulip | Chalky and alkaline suits Tulip as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Virginia creeper | Chalky and alkaline suits Virginia creeper as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Winter savory | Chalky and alkaline suits Winter savory as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Yew | Chalky and alkaline suits Yew as it stands: The free drainage is exactly what it wants. Chalky soil is among the soils it is recorded as suiting. It stands dry conditions better than most, which this soil will test. |
| Plant | Why |
|---|---|
| Agapanthus | Agapanthus grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Aloe vera | Aloe vera grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Armand clematis | Armand clematis grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Asparagus | Asparagus grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Beetroot | Beetroot grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Bird of paradise | Bird of paradise grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Broad bean | Broad bean grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Brussels sprouts | Brussels sprouts grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Chamomile | Chamomile grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Chard | Chard grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Chicory | Chicory grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Chives | Chives grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Christmas box | Christmas box grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Crab apple | Crab apple grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Crocosmia | Crocosmia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Deutzia | Deutzia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Dill | Dill grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Echeveria | Echeveria grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Evergreen climbing hydrangea | Evergreen climbing hydrangea grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Fatsia | Fatsia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Feather reed grass | Feather reed grass grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Fennel | Fennel grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Forsythia | Forsythia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Garlic | Garlic grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Garlic chives | Garlic chives grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Globe artichoke | Globe artichoke grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Golden-scaled male fern | Golden-scaled male fern grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Hart's tongue fern | Hart's tongue fern grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Haworthia | Haworthia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Hellebore | Hellebore grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Henry's honeysuckle | Henry's honeysuckle grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Heuchera | Heuchera grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Jade plant | Jade plant grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Jerusalem artichoke | Jerusalem artichoke grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Kale | Kale grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Lamb's lettuce | Lamb's lettuce grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Leek | Leek grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Lemon balm | Lemon balm grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Lemon verbena | Lemon verbena grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Lovage | Lovage grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Male fern | Male fern grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Passionflower | Passionflower grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Peony | Peony grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Rudbeckia | Rudbeckia grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Shallot | Shallot grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Snake plant | Snake plant grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Snowdrop | Snowdrop grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Soft shield fern | Soft shield fern grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Spider plant | Spider plant grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Spiraea | Spiraea grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Star jasmine | Star jasmine grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| String of hearts | String of hearts grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| String of pearls | String of pearls grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Tiger flower | Tiger flower grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Viburnum | Viburnum grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Weigela | Weigela grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
| Wisteria | Wisteria grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose. |
These crop perfectly well here once one specific thing is dealt with. The condition is stated for each, and it is usually a single job rather than an ongoing one.
| Plant | Why | What to do |
|---|---|---|
| Aglaonema | Aglaonema will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Amelanchier | Amelanchier will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Apricot | Apricot will crop on chalky and alkaline, but one thing has to be dealt with first. It roots to about 50 cm and this soil offers roughly 40 cm before rock or hardpan. | Grow it in a deep container or a raised bed. The rooting depth is not something that can be added to the ground. |
| Basil | Basil will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Blackberry | Blackberry will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Broccoli | Broccoli will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Brunnera | Brunnera will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Bugle | Bugle will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Cabbage | Cabbage will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Canna | Canna will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Carrot | Carrot will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Cauliflower | Cauliflower will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Chervil | Chervil will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Chilli pepper | Chilli pepper will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Chinese money plant | Chinese money plant will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Christmas cactus | Christmas cactus will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Clematis | Clematis will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Climbing hydrangea | Climbing hydrangea will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Coriander | Coriander will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Curry leaf | Curry leaf will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Dahlia | Dahlia will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Dragon tree | Dragon tree will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Fig | Fig will crop on chalky and alkaline, but one thing has to be dealt with first. It roots to about 45 cm and this soil offers roughly 40 cm before rock or hardpan. | Grow it in a deep container or a raised bed. The rooting depth is not something that can be added to the ground. |
| Foxglove | Foxglove will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| French bean | French bean will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Gladiolus | Gladiolus will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Gooseberry | Gooseberry will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 6.8, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Grape | Grape will crop on chalky and alkaline, but one thing has to be dealt with first. It roots to about 60 cm and this soil offers roughly 40 cm before rock or hardpan. | Grow it in a deep container or a raised bed. The rooting depth is not something that can be added to the ground. |
| Heartleaf philodendron | Heartleaf philodendron will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Hippeastrum | Hippeastrum will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Honeysuckle | Honeysuckle will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Hosta | Hosta will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Hoya | Hoya will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Kentia palm | Kentia palm will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Kohlrabi | Kohlrabi will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Lemongrass | Lemongrass will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Lily | Lily will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Loganberry | Loganberry will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Mint | Mint will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Monstera | Monstera will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Moth orchid | Moth orchid will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Onion | Onion will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Pak choi | Pak choi will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Parlour palm | Parlour palm will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Parsnip | Parsnip will crop on chalky and alkaline, but one thing has to be dealt with first. It roots to about 60 cm and this soil offers roughly 40 cm before rock or hardpan. | Grow it in a deep container or a raised bed. The rooting depth is not something that can be added to the ground. |
| Pea | Pea will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Peperomia | Peperomia will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Potato | Potatoes crop on chalk, but alkaline, free-draining soil is exactly the condition that favours common scab — the corky patches on the skin. The tubers remain perfectly edible; the crop simply looks poor, which matters more to some growers than others.recorded fact | Water consistently through tuber formation, which is the single most effective control, and choose a scab-resistant cultivar. Do not lime before potatoes. |
| Pothos | Pothos will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Redcurrant | Redcurrant will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 6.8, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Rose | Rose will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Rowan | Rowan will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 4.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Rubber plant | Rubber plant will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Sedge | Sedge will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Silver birch | Silver birch will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 4.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Spinach | Spinach will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Spring onion | Spring onion will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Swede | Swede will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Sweet pepper | Sweet pepper will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Sweetcorn | Sweetcorn will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Swiss cheese vine | Swiss cheese vine will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Syngonium | Syngonium will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Tayberry | Tayberry will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| Thai basil | Thai basil will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Turnip | Turnip will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. | Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure. |
| Whitecurrant | Whitecurrant will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 6.8, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
| ZZ plant | ZZ plant will crop on chalky and alkaline, but one thing has to be dealt with first. The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. | The pH is the obstacle. Small shifts are achievable and slow; large ones are not. On chalky and alkaline the dependable answer is a container of the right compost rather than an attempt to change the ground. |
Struggles in the open ground here. That is not the same as impossible — a container or a raised bed of imported soil sidesteps almost all of these, and for several it is the standard way of growing them anyway.
| Plant | Why |
|---|---|
| Alocasia | Alocasia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Anthurium | Anthurium struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Apple | Apple struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It roots to about 60 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Aubergine | Aubergine struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Blackcurrant | Blackcurrant struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 6.8, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Blueberry | Blueberries fail on chalk for a reason a pH comparison understates. Free calcium carbonate in the soil locks iron into forms the plant cannot take up, so the leaves yellow between the veins and the bush declines whatever is fed to it — and the chalk continues weathering into the soil, so acidifying materials are buffered away as fast as they are added. This is not a soil that can be corrected; it is a soil to grow blueberries in a pot beside. A container of ericaceous compost watered with rainwater works permanently and costs almost nothing.recorded fact |
| Boston fern | Boston fern struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Calathea | Calathea struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Camellia | Camellias cannot be grown in the ground on chalk. Free calcium carbonate locks iron into forms the plant cannot take up, so the leaves yellow between the veins and the plant declines whatever is fed to it — and the chalk keeps weathering into the soil, so acidifying materials are buffered away as fast as they are added. The pH numbers alone understate this: it is not a preference missed by a point, it is a hard chemical limit.recorded fact |
| Celeriac | Celeriac struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Celery | Celery struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Cherry | Cherry struggles on chalky and alkaline: It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. It roots to about 50 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Courgette | Courgette struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Cucumber | Cucumber struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Dieffenbachia | Dieffenbachia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Endive | Endive struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Fittonia | Fittonia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Fuchsia | Fuchsia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Hydrangea | Hydrangea struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Japanese forest grass | Japanese forest grass struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Japanese maple | Japanese maple struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 6.8, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Lady fern | Lady fern struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Land cress | Land cress struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Lettuce | Lettuce struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Magnolia | Magnolia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 6.8, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Melon | Melon struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Ostrich fern | Ostrich fern struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Parsley | Parsley struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Peace lily | Peace lily struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Peach | Peach struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It roots to about 50 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Pear | Pear struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It roots to about 60 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Pieris | Pieris struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 4.5 to 6, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Plum | Plum struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It roots to about 50 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Pumpkin | Pumpkin struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Quince | Quince struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It roots to about 50 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Radish | Radish struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Raspberry | Raspberry struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Rhododendron | The same iron lock-out as camellia, and the reason healthy rhododendrons in neighbouring gardens are the most reliable free soil test available. On chalk this is a container plant of ericaceous compost or nothing at all.recorded fact |
| Rhubarb | Rhubarb struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. It roots to about 45 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Rocket | Rocket struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Royal fern | Royal fern struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 4.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Runner bean | Runner bean struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Shiso | Shiso struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Skimmia | Skimmia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Sorrel | Sorrel struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Strawberry | Strawberry struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Tomato | Tomato struggles on chalky and alkaline: It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. It roots to about 45 cm and this soil offers roughly 40 cm before rock or hardpan. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Tuberous begonia | Tuberous begonia struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 6.5, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Vietnamese coriander | Vietnamese coriander struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 5.5 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
| Winter squash | Winter squash struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely. |
Each of these states its ceiling as well as its effect, because every soil improvement is oversold somewhere and a gardener who knows where it stops does not keep going for another three years.
Improves structure on every soil type: it binds sand into crumbs that hold water and nutrients, and opens clay so air and roots can get through. It also feeds the soil biology that maintains the structure once it exists.
Horticultural consensusmoderate confidence
Checked 2026-08-13
What it will not do: It will not change what the soil is made of. Clay with twenty years of compost in it is well-structured clay, not loam, and it will still be sticky in a wet February. Nor does it meaningfully move pH.
Manure must be well rotted. Fresh manure scorches roots and robs nitrogen from the soil as it breaks down, and manure from an unknown source can carry residues of persistent broad-leaved herbicides that damage potatoes, tomatoes and beans for several seasons.
Sourced guidancehigh confidence
Checked 2026-08-13
Slows evaporation from the surface, so a droughty soil holds what it is given for longer. It also suppresses annual weeds and protects the surface from the impact of heavy rain, which is what causes capping.
Horticultural consensusmoderate confidence
Checked 2026-08-13
What it will not do: It does not add water. Mulch applied to dry ground keeps it dry — the soil must be moist when the mulch goes on, which in practice means spring after rain rather than midsummer.
Gives a straight, stone-free run for a taproot to grow down. A forked carrot is a root that met an obstacle, and no amount of soil improvement removes the stones from a stony soil.
Sourced guidancehigh confidence
Checked 2026-08-13
What it will not do: It does nothing for the rest of the garden, and it is not a general fix — it addresses one specific failure of one group of crops. Sieving stones out of an open bed is possible and rarely worth the labour, as more work upwards each year.
On a soil containing free chalk, essentially nothing that lasts. The calcium carbonate buffers against acidifying materials as fast as they are added, so sulphur, ericaceous feeds and sequestered iron produce a temporary shift and are then re-applied indefinitely. On a merely neutral soil with no free chalk, a modest and slow reduction is achievable.
GrowingHQ editorial positionhigh confidence
Presented as a negative recommendation because the alternative — a container of ericaceous compost — is cheap, immediate and permanent, and because a reader who spends three years acidifying a chalk bed has been given the mechanism but not the conclusion.
Checked 2026-08-13
What it will not do: It will not give a chalk garden an acid bed. The chalk is the parent material of the soil and continues to weather into it; the buffering is not a temporary obstacle to be overcome but the permanent condition of the site.
Where an acid-loving plant is genuinely wanted on chalk, grow it in a container of ericaceous compost and water it with rainwater. A raised bed filled with ericaceous compost over chalk gradually reverts as the ground below leaches upwards into it, so the container is the more dependable of the two.
Sourced guidancehigh confidence
Checked 2026-08-13
All ten interventions, compared, including the ones that do not apply here.
Soil record reviewed 2026-08-14.