Although it is a member of the potato family, (just look at the flower), it comes from Asia. Unfortunately, aubergines take a long time to reach maturity in the North of the UK, and the best results are obtained by growing a quick growing variety.
The seed is best started in heat in February or March in individual cells, and then transplanted in May (three plants to a grow bag) into a hot or cool greenhouse. The latest quick growing varieties should be ready by August in a cool greenhouse. Use your tomato fertiliser.
For growing them outside in the South of the UK, start them in heat as before and transplant them in June after all danger of frost. Even so, they will do better with cloche protection.
Hand pollination in a greenhouse may be necessary and is easily achieved by tapping the flower with a finger to spread the pollen.
Aubergines are ready when they reach the expected size for the particular variety, usually about 20 weeks after sowing the seed, and growing in a greenhouse. Check the seed packet or catalogue for the expected size. If you do not know the variety, then keep an eye on the growth of the first aubergine, and when it seems to stop getting any bigger, it is probably about ready. In addition, the skin should still be shiny. If the skin has become dull, or they have brown patches on the skin, they are well past their best, and the seeds will be very obvious and starting to colour inside the aubergine. If in doubt, pick the first one to check for ripeness and use.
Pests and diseases. While greenfly, whitefly can be a nuisance, red spider mites are a constant problem in the greenhouse and spraying is required as soon as they are spotted.
Apple Green. This is a small variety, about the size of a goose egg, but it is extremely early, some 4 weeks before standard varieties. Allow 75 days from transplanting.
Listada de Gandia. This is a very pretty striped standard variety. Allow about 105 days from transplanting.
Ophelia. Compact, heavy purple fruiting variety.