Growing Aubergines or Eggplants
Also known as the egg plant because of its smooth skin and ovoid shape, the aubergine is a native of tropical Asia, though extensively cultivated elsewhere. For this reason, in the British Isles it is most likely to succeed when grown in a greenhouse.
Only in a long, hot summer, when planted against a south-facing wall, is it possible to grow it successfully outdoors. In this case it helps to give the plants a sheltered start under frames or cloches after raising the seedlings in a greenhouse or indoors.
A sunny patio also provides reasonable conditions for growing aubergines outdoors — either in pots or in the bags of compost sold by garden shops.
Planning the crop
In a greenhouse, grow aubergines in 7 in. (180 mm) pots or plant them in the border. If grown outdoors, choose a position that is open to the sun for most of the day. They require well-drained soil, liberally dressed with manure.
How many to grow
The space available in the greenhouse will generally determine the number of plants to be grown. Space the pots about 18 in. (455 mm) apart, and allow a similar space between outdoor plants.
Indoors, you can expect up to about 12 fruits on each plant. Outdoors, up to four.
Two varieties are commonly grown:
`Blanche Longue de la Chine’: good-sized fruits with a white outer skin.
`Early Long Purple’: large, long fruits of fine flavour.
How to grow aubergines
For growing in a greenhouse or outdoors, sow the aubergines in seed compost in February. The temperature needs to be 18°C (64°F), so place the seed pan in a propagator or close to the heat source in the greenhouse.
When large enough to handle, prick the plants out singly into 3 in. (75 mm) pots of John Innes No. 1 compost or a soil-less potting compost. Grow them on in a temperature of about 16°C (61°F).
If the plants are to be grown indoors, transfer them to 7 in. (180 mm) pots of John Innes No. 2 compost when they are 4-6 in. (100-150 mm) tall. Alternatively, plant them in the border.
Harden off outdoor plants during May and plant them at the end of the month, spacing them 18 in. (455 mm) apart. Protect with a cloche or frame until they are well established. For growing on a patio, plant in 7 in. (180 mm) pots or in plastic bags filled with compost.
When the plants are about 9 in. (230 mm) high, pinch out the tops to encourage them to bush.
On indoor plants, allow up to three fruits to form on each of the three or four lateral branches that will develop. Outdoors, pinch out the tips of each branch once a fruit has formed on it, leaving three leaves beyond the fruit.
Indoors and out, remove side-shoots that form on laterals.
Water generously and give weekly feeds of liquid manure once the fruits are visible. Spray the leaves with water regularly to keep down red spider mites.
Pests and diseases
Aphids and glass red spider mites are the pests most likely to affect aubergines. The plants are generally disease-free.
Aubergines are ripe when their colour becomes an overall black-purple or ivory-white, depending on variety, which will be between July and October for greenhouse crops and a month or more later outdoors. Handle the fruits carefully and remove by snipping the stems with scissors.
Aubergines can be kept for about a fortnight after harvesting.