outdoorgrowing medium
Container
Pots, troughs, tubs and grow bags outdoors. Rooting volume is fixed and small, which changes almost everything about watering and feeding.
What this changes about growing
- Watering is the binding constraint: a full-grown plant in a small pot on a hot day can need water twice.
- Nutrients are exhausted or leached within weeks, so feeding is not optional as it often is in the ground.
- Roots are exposed to air temperature on all sides, so containers freeze harder and heat faster than soil.
- Container size is a real horticultural variable, not a matter of taste — it sets the ceiling on what the plant can become.
What GrowingHQ has assessed in it
Only plants with an actual assessment appear here. A plant that is absent has not been ruled out — it has not been looked at for this method.
| Plant | Suitability | What it needs |
|---|---|---|
| Agapanthus | Well suited | |
| Aglaonema | Well suited | Indoors, or outdoors in summer only |
| Alocasia | Well suited | Indoors, or outdoors in summer only |
| Aloe vera | Well suited | Indoors, or outdoors in summer only |
| Anthurium | Well suited | Indoors, or outdoors in summer only |
| Aubergine | Well suited | 10 litres per plant; Under cover |
| Basil | Well suited | A warm sheltered spot; 3–5 litres per plant |
| Bay | Well suited | 30 litres; Free-draining compost; Somewhere sheltered from cold wind |
| Beetroot | Well suited | A pot at least 20 cm deep |
| Bird of paradise | Well suited | Indoors, or outdoors in summer only |
| Blue fescue | Well suited | |
| Blueberry | Well suited | Ericaceous compost; 30 litres or more; RainwaterThe recommended method in Britain, because it puts the pH under the grower's control. |
| Boston fern | Well suited | Shade; Indoors, or outside in summer shade |
| Bugle | Well suited | |
| Calathea | Well suited | Indoors only |
| Camellia | Well suited | 40 litres; Ericaceous compost; Rainwater where the tap water is hard |
| Canna | Well suited | |
| Carrot | Well suited | 30 cm deep for maincrops, 15–20 cm for short cultivars |
| Chamomile | Well suited | 5 litres; Free-draining compost |
| Chard | Well suited | 10 litres; 25 cm deep |
| Chervil | Well suited | 5 litres; A shaded position |
| Chilli pepper | Well suited | A warm sheltered spot outdoors, moved under cover in autumn |
| Chinese money plant | Well suited | Indoors, or outdoors in summer only |
| Chives | Well suited | A permanent container herb that survives being forgotten and comes back each spring. |
| Christmas box | Well suited | |
| Christmas cactus | Well suited | Indoors, or outdoors in summer only |
| Coriander | Well suited | 20 cm of depth; Sown direct rather than transplanted |
| Crocus | Well suited | |
| Curry leaf | Well suited | 20 litres; A minimum of 10 °C all winter |
| Daffodil | Well suited | |
| Dahlia | Well suited | 20 litres; Staking for tall cultivars |
| Dieffenbachia | Well suited | Indoors, or outdoors in summer only |
| Dragon tree | Well suited | Indoors, or outdoors in summer only |
| Echeveria | Well suited | Indoors, or outdoors in summer only |
| Fatsia | Well suited | |
| Fig | Well suited | 35 litres or more; A sunny sheltered positionThe container provides the root restriction the plant needs to fruit, which makes this the rare case where a pot is better than the ground. |
| Fittonia | Well suited | Indoors, or outdoors in summer only |
| French bean | Well suited | A dwarf cultivar; 15 litres or more |
| Fuchsia | Well suited | 10 litres; Reliable watering — baskets dry out fast |
| Garlic chives | Well suited | 5 litres |
| Grape hyacinth | Well suited | |
| Hard shield fern | Well suited | |
| Hardy cyclamen | Well suited | |
| Hart's tongue fern | Well suited | |
| Haworthia | Well suited | Indoors, or outdoors in summer only |
| Heartleaf philodendron | Well suited | Indoors, or outdoors in summer only |
| Hebe | Well suited | 15 litres; Free-draining compost |
| Heuchera | Well suited | |
| Hippeastrum | Well suited | |
| Hosta | Well suited | 15 litres; Raised or on pot feet — much easier to defend from slugs |
| Hoya | Well suited | Indoors, or outdoors in summer only |
| Hyacinth | Well suited | |
| Hydrangea | Well suited | 30 litres; Reliable watering — it will not forgive a dry fortnight |
| Hyssop | Well suited | 10 litres; Gritty free-draining compost |
| Jade plant | Well suited | Indoors, or outdoors in summer only |
| Japanese forest grass | Well suited | |
| Jerusalem artichoke | Well suited | 30 litres; Chosen for containment rather than for space |
| Kale | Well suited | 15 litres or more per plant |
| Kentia palm | Well suited | Indoors, or outdoors in summer only |
| Kohlrabi | Well suited | 10 litres; 25 cm deep |
| Lamb's lettuce | Well suited | 3 litres; 12 cm deep |
| Land cress | Well suited | |
| Lavender | Well suited | 10 litres; Gritty free-draining compost |
| Lemon balm | Well suited | 7 litres; Chosen for containment as much as for space |
| Lemon thyme | Well suited | 5 litres; Gritty free-draining compost |
| Lemon verbena | Well suited | 20 litres; Somewhere frost-free for winter |
| Lemongrass | Well suited | 10 litres; Moved under cover from October |
| Lettuce | Well suited | 15 cm of depth is enough; Watering little and often |
| Lily | Well suited | |
| Maidenhair spleenwort | Well suited | |
| Marjoram | Well suited | 4 litres; Free-draining compost |
| Mexican feather grass | Well suited | |
| Mint | Well suited | 5 litres or more; Consistent moistureThe recommended way to grow it outdoors, precisely because it confines the runners. |
| Monstera | Well suited | Indoors, or outdoors in summer only |
| Moth orchid | Well suited | Indoors only |
| Nerine | Well suited | |
| Oregano | Well suited | Gritty compost; Sparing watering |
| Pak choi | Well suited | 8 litres; 20 cm deep |
| Parlour palm | Well suited | Indoors, or outdoors in summer only |
| Parsley | Well suited | 25 cm of depth for the taproot |
| Peace lily | Well suited | Indoors, or outdoors in summer only |
| Peperomia | Well suited | Indoors, or outdoors in summer only |
| Pieris | Well suited | |
| Potato | Well suited | A 30–40 litre bag or tub; Two or three seed tubers per container; Consistent watering once the foliage is upFirst earlies in a bag are one of the best returns available to a grower with no ground at all. |
| Pothos | Well suited | Indoors, or outdoors in summer only |
| Radish | Well suited | 15 cm of depth is enough |
| Rhododendron | Well suited | 40 litres; Ericaceous compost; Rainwater where possible |
| Rocket | Well suited | 4 litres; 15 cm deep |
| Rosemary | Well suited | Gritty free-draining compost; 15 litres or more; Sparing watering |
| Rubber plant | Well suited | Indoors, or outdoors in summer only |
| Sage | Well suited | Gritty compost; 10 litres or more |
| Salad burnet | Well suited | 7 litres |
| Salvia | Well suited | 10 litres; Free-draining compost |
| Savory | Well suited | |
| Sedge | Well suited | |
| Shallot | Well suited | 10 litres; 20 cm deep |
| Shiso | Well suited | 7 litres |
| Skimmia | Well suited | |
| Snake plant | Well suited | Indoors, or outdoors in summer only |
| Sorrel | Well suited | |
| Spider plant | Well suited | Indoors, or outdoors in summer only |
| Spinach | Well suited | 20 cm of depth; Consistent moisture |
| Spiraea | Well suited | |
| Spring onion | Well suited | 5 litres; 15 cm deep |
| Star jasmine | Well suited | |
| Strawberry | Well suited | 5 litres per plant; Consistent wateringKeeps the fruit off the soil, which deals with both slugs and grey mould. |
| String of hearts | Well suited | Indoors, or outdoors in summer only |
| String of pearls | Well suited | Indoors, or outdoors in summer only |
| Sweet pepper | Well suited | 10–15 litres per plant; A warm sheltered position, ideally against a south-facing wall |
| Swiss cheese vine | Well suited | Indoors, or outdoors in summer only |
| Syngonium | Well suited | Indoors, or outdoors in summer only |
| Tarragon | Well suited | 7 litres; Gritty free-draining compost |
| Thai basil | Well suited | 5 litres |
| Thyme | Well suited | Gritty compost; Sparing watering |
| Tomato | Well suited | At least 20 litres per cordon plant; Watering once or twice daily in hot weather; A high-potassium feed once fruit has set |
| Tuberous begonia | Well suited | |
| Tulip | Well suited | |
| Vietnamese coriander | Well suited | 5 litres; Compost kept constantly moist |
| Winter savory | Well suited | 7 litres; Gritty free-draining compost |
| ZZ plant | Well suited | Indoors, or outdoors in summer only |
| Apple | Workable | A very dwarfing rootstock such as M27; 45 litres or more; Permanent staking |
| Apricot | Workable | 45 litres or more; Somewhere frost-free to stand it while in flower |
| Berberis | Workable | |
| Blackcurrant | Workable | 45 litres or more; Annual feeding |
| Borage | Workable | 10 litres; Support in an exposed spot |
| Broad bean | Workable | A dwarf cultivar; 20 litres or more |
| Broccoli | Workable | |
| Brunnera | Workable | |
| Cabbage | Workable | 20 litres per plant; A compact cultivar |
| Chicory | Workable | |
| Clematis | Workable | 40 litres; Compact cultivars; Shade over the pot |
| Cotoneaster | Workable | |
| Courgette | Workable | 30 litres or more; Daily watering in hot weather |
| Crocosmia | Workable | |
| Cucumber | Workable | 20 litres or more; Support; Water at least daily in hot weather |
| Deutzia | Workable | |
| Dill | Workable | 25 cm of depth; Shelter from wind |
| Echinacea | Workable | |
| Endive | Workable | |
| Epimedium | Workable | |
| Feather reed grass | Workable | |
| Fennel | Workable | 10 litres; 30 cm deep |
| Garlic | Workable | A pot left outdoors through winter so the cold requirement is met |
| Gladiolus | Workable | |
| Golden-scaled male fern | Workable | |
| Gooseberry | Workable | |
| Hardy geranium | Workable | |
| Hellebore | Workable | |
| Henry's honeysuckle | Workable | |
| Holly | Workable | |
| Honeysuckle | Workable | |
| Ivy | Workable | |
| Japanese maple | Workable | |
| Lady fern | Workable | |
| Leek | Workable | 30 cm deep so there is room to blanch the shank |
| Male fern | Workable | |
| Melon | Workable | 30 litres or more; Under cover |
| Mexican orange blossom | Workable | |
| Miscanthus | Workable | |
| Ornamental allium | Workable | |
| Osmanthus | Workable | |
| Passionflower | Workable | |
| Pea | Workable | A dwarf cultivar; 20 litres or more |
| Peach | Workable | 45 litres or more; Somewhere frost-free and dry to stand it from midwinter |
| Periwinkle | Workable | |
| Raspberry | Workable | An autumn cultivar; 30 litres or more; Ericaceous or neutral compost |
| Redcurrant | Workable | 35 litres or more |
| Rose | Workable | 30 litres minimum; Loam-based compost; Patio cultivars |
| Rudbeckia | Workable | |
| Runner bean | Workable | |
| Snowdrop | Workable | |
| Soft shield fern | Workable | |
| Tiger flower | Workable | |
| Turnip | Workable | 25 cm deep |
| Viburnum | Workable | |
| Whitecurrant | Workable | |
| Yew | Workable | |
| Amelanchier | Marginal | |
| Armand clematis | Marginal | |
| Bearded iris | Marginal | |
| Blackberry | Marginal | |
| Buddleja | Marginal | Dwarf cultivars only |
| Californian lilac | Marginal | |
| Cauliflower | Marginal | 20 litres and firm compost; Reliable watering |
| Celeriac | Marginal | |
| Celery | Marginal | Very reliable watering |
| Climbing hydrangea | Marginal | |
| Crab apple | Marginal | |
| Escallonia | Marginal | |
| Evergreen climbing hydrangea | Marginal | |
| Firethorn | Marginal | |
| Forsythia | Marginal | |
| Foxglove | Marginal | |
| Globe artichoke | Marginal | Very large — 40 litres minimum, and still smaller than in the ground |
| Grape | Marginal | |
| Hawthorn | Marginal | |
| Loganberry | Marginal | |
| Lovage | Marginal | Too large to be sensible in anything but a half-barrel |
| Magnolia | Marginal | |
| Mahonia | Marginal | |
| Mock orange | Marginal | |
| Onion | Marginal | |
| Ostrich fern | Marginal | |
| Parsnip | Marginal | 45 cm deep minimum; Long occupancy makes it a poor container choice |
| Peony | Marginal | |
| Plum | Marginal | |
| Rhubarb | Marginal | |
| Rowan | Marginal | |
| Royal fern | Marginal | |
| Silver birch | Marginal | |
| Swede | Marginal | Large and long-season — a poor use of container space |
| Sweetcorn | Marginal | 20 litres each, and several grouped together for pollination |
| Tayberry | Marginal | |
| Virginia creeper | Marginal | |
| Weigela | Marginal | |
| Winter squash | Marginal | 40 litres; Bush forms only |
| Wisteria | Marginal | |
| Asparagus | Not suitable | A permanent deep-rooted bed — containers cannot support it |
| Brussels sprouts | Not suitable | Too tall and too top-heavy for any practical container |
| Pumpkin | Not suitable |