Growing Aubergines Outdoors
In mid-spring, begin hardening off the plants, which by then will be in their 7.5 cm (3”) pots, ideally in a cold frame. Open the light during the day, and shut it at night or when the weather turns cold. In early summer, when all danger of frost is over, plant them out, spaced 60 cm (2’) apart. If theis dry at the time of transplanting, water both the plants and the permanent bed thoroughly the night before.
If you want to try sowing aubergine seeds outdoors, warm the soil up first. Place cloches over the soil about a fortnight before you intend sowing, and immediately after sowing, return the cloches so they provide warmth for the germinating seeds. The seeds should be sown in drills 2.5 cm (1”) deep; as they are large they can be sown singly, about 30 cm (1’) apart, and later thinned to a spacing of 60 cm (2’). If you have more than one row, space them 60 cm (2’) apart also.
Care and cultivation
Pinch out the growing points of the plants when they are about 15 cm (6”) high. This encourages the plants to produce sideshoots, on which the mauve, self-pollinating flowers will later form, though the fruit will be produced slightly later than if not pinched.
Keep the plants well supplied with water, particularly in hot, dry weather. Spread a mulch of lawn mowings or straw around the plants, once they are growing well, to conserve soil moisture and suppress. Once the flowers have set, use a proprietary tomato fertilizer at the manufacturer’s recommended rates.
Red spider mite can be troublesome during mid- to late summer, if the weather is hot and dry. The best precaution is to syringe the plants daily with tepid water, carefully wetting the undersides of the leaves. Do not syringe or water unnecessarily, though, because an excessively moist atmosphere could encourage attack by botrytis, especially if the summer is a cool one, or the night temperature tends to be rather low.
The plants will need staking, particularly if they are exposed to strong wind. Use bamboo canes at least 1.2 m (4’) long, set 30 cm (1’) into the soil.
Plants growing under cloches must have adequate head room; ultimately 90-105 cm (3’-3’6”) will be needed. Stand the cloches on end, two to a plant, and place them on bricks to give additional height if necessary. You can remove the cloches completely if the summer is a verv hot one.
Although many fruitlets may form, in cool temperate climates it is best to restrict the number of fruits to a maximum of four per plant. Pinch out the additional fruitlets, so that all plant’s energy is concentrated on the production of the four selected fruits.