protectedsoil
Greenhouse
A glazed structure a person can work in, heated or unheated, used to extend the season at both ends and to grow crops that will not ripen outdoors.
What this changes about growing
- Warmth and shelter let tender fruiting crops finish reliably in climates where they would not outdoors.
- Ventilation is the main daily job: a closed greenhouse in spring sunshine can exceed 40 °C within an hour.
- Humidity and still air favour fungal disease and glasshouse pests, which is the price of the protection.
- Pollination of fruiting crops can need help where insects cannot get in.
Safety
Any electrical supply to a greenhouse is an outdoor supply next to water and must be installed accordingly.
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 |
|---|---|---|
| Alocasia | Well suited | |
| Aloe vera | Well suited | |
| Anthurium | Well suited | |
| Apricot | Well suited | Hand pollination; Summer ventilation |
| Aubergine | Well suited | A long season and warmth into autumn |
| Basil | Well suited | |
| Beetroot | Well suited | |
| Bird of paradise | Well suited | |
| Boston fern | Well suited | |
| Broccoli | Well suited | |
| Cabbage | Well suited | |
| Calathea | Well suited | A heated humid greenhouse suits it far better than a house does. |
| Chard | Well suited | |
| Chicory | Well suited | |
| Chilli pepper | Well suited | |
| Chives | Well suited | |
| Cucumber | Well suited | An all-female greenhouse cultivar; Vertical support; Humid air and steady moistureGreenhouse cucumbers want it warmer and more humid than tomatoes; sharing one small greenhouse between the two is always a compromise. |
| Endive | Well suited | |
| Fennel | Well suited | |
| Fig | Well suited | Ripens fruit far more reliably and produces a second crop in a good year. |
| Fittonia | Well suited | |
| Fuchsia | Well suited | How tender cultivars are overwintered. |
| Grape | Well suited | A permanent rod-and-spur framework; Summer ventilationThe traditional way to ripen dessert grapes in Britain, often with the roots outside and the rod led in through the wall. |
| Hoya | Well suited | |
| Jade plant | Well suited | |
| Kale | Well suited | |
| Lamb's lettuce | Well suited | |
| Land cress | Well suited | |
| Lemon balm | Well suited | |
| Lemon verbena | Well suited | |
| Lemongrass | Well suited | |
| Lettuce | Well suited | |
| Marjoram | Well suited | |
| Melon | Well suited | Vertical support; Hand pollination; Slings under swelling fruit |
| Mint | Well suited | |
| Monstera | Well suited | |
| Moth orchid | Well suited | |
| Pak choi | Well suited | |
| Parsley | Well suited | |
| Passionflower | Well suited | |
| Peach | Well suited | Hand pollination; Ventilation in summerUnder glass the leaf-curl problem largely disappears, which is the strongest argument for growing peaches this way. |
| Rocket | Well suited | |
| Rubber plant | Well suited | |
| Savory | Well suited | |
| Shiso | Well suited | |
| Sorrel | Well suited | |
| Spring onion | Well suited | |
| Sweet pepper | Well suited | Ventilation in high summer |
| Thai basil | Well suited | |
| Tomato | Well suited | Daily ventilation in summer; Support for cordon types to the roofThe reliable option in Britain: warmth, a longer season and rain kept off the leaves, which is most of the blight problem solved. |
| Turnip | Well suited | |
| Vietnamese coriander | Well suited | |
| Bay | Workable | |
| Borage | Workable | |
| Broad bean | Workable | |
| Camellia | Workable | |
| Carrot | Workable | |
| Cauliflower | Workable | |
| Celeriac | Workable | |
| Celery | Workable | |
| Chamomile | Workable | |
| Chervil | Workable | |
| Coriander | Workable | |
| Curry leaf | Workable | Only a heated one. |
| Dahlia | Workable | |
| Dill | Workable | |
| French bean | Workable | |
| Garlic chives | Workable | |
| Hyssop | Workable | |
| Kohlrabi | Workable | |
| Lavender | Workable | |
| Lemon thyme | Workable | |
| Pea | Workable | |
| Potato | Workable | |
| Radish | Workable | |
| Raspberry | Workable | |
| Rhubarb | Workable | |
| Rosemary | Workable | Chiefly for overwintering container plants in cold districts. |
| Sage | Workable | For overwintering container plants in cold districts. |
| Salad burnet | Workable | |
| Spinach | Workable | |
| Strawberry | Workable | Hand pollination if insects cannot reach the flowers |
| Sweetcorn | Workable | |
| Tarragon | Workable | |
| Winter savory | Workable | |
| Winter squash | Workable | |
| Apple | Marginal | |
| Asparagus | Marginal | |
| Blackberry | Marginal | |
| Blackcurrant | Marginal | |
| Blueberry | Marginal | |
| Brussels sprouts | Marginal | |
| Cherry | Marginal | |
| Courgette | Marginal | |
| Garlic | Marginal | |
| Globe artichoke | Marginal | |
| Gooseberry | Marginal | |
| Leek | Marginal | |
| Loganberry | Marginal | |
| Lovage | Marginal | |
| Onion | Marginal | |
| Oregano | Marginal | |
| Parsnip | Marginal | |
| Pear | Marginal | |
| Plum | Marginal | |
| Pumpkin | Marginal | |
| Quince | Marginal | |
| Redcurrant | Marginal | |
| Runner bean | Marginal | |
| Shallot | Marginal | |
| Swede | Marginal | |
| Tayberry | Marginal | |
| Thyme | Marginal | |
| Whitecurrant | Marginal | |
| Jerusalem artichoke | Not suitable |
Ready-made lists from this group
Built from the same assessments as the table above, filtered to the question a person standing in front of the structure is actually asking.