Quick answer
Start aubergines—called eggplant in North America—indoors with heat and bright light, then grow them in a greenhouse or the warmest sheltered outdoor position. Give each plant full sun, a 15-litre or larger container, reliable water and feeding after flowers appear. Cut fruits while their skin is glossy and flesh still feels firm.
In cool climates, warmth is the limiting factor. A healthy plant can fail to crop if nights remain cold or the season is too short. Compact, early, small-fruited cultivars are more reliable outdoors than varieties bred for long, hot summers.
Choose a cultivar for the site
Aubergines may be oval, round, long or finger-shaped, with purple, white, green, striped or pink skin. Fruit size is not a maturity test by itself. Use the cultivar description to learn the expected colour and dimensions.
For an unheated greenhouse, prioritise early maturity and manageable height. For a warm patio, choose a compact cultivar described for containers. Grafted plants cost more but can be vigorous in marginal conditions. Large-fruited cultivars need more time and may require stronger support.
Aubergines share their family with tomatoes, peppers and potatoes. Rotate these solanaceous crops where soil-borne wilt or other recurring diseases have occurred.
Temperature, light and soil
Provide at least six hours of direct sun and sustained warmth. The RHS aubergine guide recommends greenhouse production for dependable UK cropping, with outdoor growing mainly in mild locations or long, hot summers.
Use fertile, free-draining soil or peat-free potting compost around pH 5.5–7.5. Enrich garden beds with mature compost. Avoid waterlogged ground and cold, exposed locations.
Do not plant outside merely because the frost date has passed. The University of Minnesota Extension advises waiting until night temperatures remain above about 10°C. Chilled plants can stall for weeks and never fully recover.
Sowing and raising plants
Sow indoors about eight to ten weeks before the intended planting time. Germination needs warmth—roughly 21–29°C—and compost dries faster on a heat mat, so check it frequently. Once seedlings emerge, give them strong overhead light and slightly cooler air.
Move seedlings into individual pots after true leaves appear. Pot on before roots become congested, keeping plants bright and warm. Pinch off very early flowers if the plant is still in a small pot; root and leaf growth should be established before fruiting.
Harden plants gradually. In a heated greenhouse they may reach final positions earlier; an unheated greenhouse follows later; outdoor planting waits until frost danger and cold nights have passed.
Planting, spacing and containers
Space plants 45–60cm apart so leaves receive light and air can move. Set at the same depth as in the pot and avoid damaging the root ball. Install a cane, cage or other support immediately rather than pushing it through established roots later.
Use one compact plant in at least a 15-litre pot around 30cm wide; 20–30 litres makes moisture management easier. Growing bags can work if each plant receives comparable root volume. Dark containers heat rapidly, so shade the root vessel if compost becomes excessively warm.
In a greenhouse border, renew or manage soil to reduce pest, salt and disease build-up. Do not assume protected soil is automatically healthy.
Watering, feeding and plant shape
Maintain even root moisture. Drought causes flower drop, bitterness and low yield; saturation excludes oxygen and encourages root disease. Water the compost or soil rather than wetting foliage, and ventilate greenhouses in hot weather.
Begin a labelled high-potassium liquid feed when the first fruits set in containers. Plants in rich ground may need less. Excess nitrogen delays fruiting by producing leaves.
For many cultivars, pinching the main tip when the plant is about 30cm tall encourages branches. Remove only unproductive lower leaves or overcrowded shoots; harsh pruning exposes fruit to sunscald. Support heavy fruits individually if needed.
Flowers and fruit set
Aubergine flowers are self-fertile, but movement helps release pollen. Gently tap supports or brush flowers in a greenhouse when insects are scarce. Very cold or very hot conditions can reduce fruit set.
Do not mistake a fallen flower for a pollination problem without checking temperature, moisture and plant health. A young plant often sheds blossoms it cannot yet support.
Diagnosing common problems
| Symptom | Likely causes to investigate | First checks |
|---|---|---|
| Flowers drop without fruit | Cold nights, heat, drought or immature plant | Temperature and root moisture |
| Leaves have many tiny holes | Flea beetles | Small jumping beetles and new growth |
| Fine webbing and bronzed leaves | Spider mites | Leaf undersides and hot, dry conditions |
| Lower leaves wilt and yellow | Verticillium wilt or root stress | Soil history, drainage and progression |
| Fruit has pale papery patch | Sunscald | Leaf cover and recent heat |
| Fruit is dull with hard seeds | Over-mature harvest | Skin gloss and firmness |
| Dark patch at blossom end | Blossom-end rot linked to calcium uptake stress | Moisture consistency and roots |
Harvest and storage
Clip fruit with secateurs, retaining a short stem and taking care around prickly calyces. Harvest when skin is glossy and fruit springs back slightly under gentle pressure. A dull skin, tough flesh and brown hard seeds indicate over-maturity.
Regular picking encourages further flowers while warmth lasts. Aubergines are sensitive to chilling and store only briefly; keep them cool but not for long periods at refrigerator-cold temperatures. Handle gently because bruises decay quickly.
Never eat leaves or stems. The cultivated fruit is the edible part, prepared normally for the variety.
Sources and review basis
- How to grow aubergines — Royal Horticultural Society
- Growing eggplant in home gardens — University of Minnesota Extension
Outdoor reliability, pruning and fruit count depend on climate and cultivar.