How to Grow Eggplant (Aubergine)

Botanical Name: Solanum melongena

Plant Type: Tender Perennial

Eggplants constitute a small group of closely related species of the family Solanaceae. The species most commonly encountered in cultivation is Solanum melongena, and other species include S. ferox, S. torvum and the red-fruited eggplants of S. integrifolium. In many old gardening books, eggplants are known by their French name of aubergines, and they are sometimes called this by older members of the gardening community in this country too.

Eggplants come from tropical Asia. They are now part of the cuisine from Greece (moussaka) to Japan (pickles). They range from the voluptuous ‘Long Purple’, delicately streaked ‘Listada di Gandia’, orange Turkish varieties, and the white globe-shaped fruit that gave then their present common name.

Varieties

Eggplants are the beauty queen of the summer vegetable garden, and with as many different varieties available as there are tomatoes, eggplants come in a variety of different colours, shapes and sizes, with equally diverse flavours and uses.

Cultivation

Hot, well-exposed sites in the garden are the best places to establish eggplants. In order to set fruit eggplants, require night-time temperatures exceeding 20°C, which can be a problem in cooler areas. One idea for cultivation in cooler regions is to establish plants in front of a wall, which provides extra heat to the plants through reflection and radiation.

Soil preparation and management for eggplants is similar to that of tomatoes, though, being slower growing, they are more easily killed by light frosts for some time after transplant, so frost protection should be available if frost effect your area.

Most varieties of eggplant should be staked to provide additional support to their branches during cropping. Without staking, large branches may succumb to the sheer mass of fruit or stress applied by wind and your fruit will be ruined before it has an opportunity to ripen.

Sun: Full sun

Pollination: Insect pollination & Self Pollination

Soil: Preferring similar growing conditions to tomatoes, improve soil prior to planting by incorporating organic material such as decomposed manure and well-rotted compost to your garden bed, and dig down at least 2 spade depths to create a deep soil profile. Raised beds are ideal in areas where drainage could be an issue as eggplants dislike waterlogging.

Growing from Seed

Sow: Sow in punnets to transplant after frosts.

Ease of Germination: Medium

Germination Temperature: 20-30°C

Germination Time: 7-14 days

Spacing: 60cm

Harvest: 50 – 80 days from transplant

Yield: 3 - 8 kg per plant

Sow eggplant seed in punnets or individual pots at least 6-8 weeks prior to your planned transplant date. Seed should be sown around 5-6mm deep and kept moist, but not wet. A heat mat will help with germination as eggplants require a soil temperature around 21°C for optimal germination. Use a premium seed raising mix to help plants through this early phase. As seedlings grow, they can be transplanted into larger pots or planted out into the garden as long as the weather has warmed and there is no likelihood of frost.

Maintenance and Additional Care

Water eggplants regularly and fertilize every 2-4 weeks with a liquid fertilizer such as Ocean Brew. Avoid overhead watering which can cause fungal problems.

Stay on top of staking to enable plants to bear their maximum crop without breaking. Harvest regularly to encourage further fruiting. If protected from frosts or grown in pots where they can be moved to a protected area, eggplants will provide you with a steady summer harvest for 3-4 years.

Companion Planting

Good companions: Basil, Beans, Marjoram, Potato and Spinach.

Bad companions: Tomato and Stone Fruit.

Pests and Diseases

Provided environmental conditions are correct, eggplants usually suffer few serious setbacks. Verticillium and Fusarium wilts can be a serious problem if present in the soil but are usually avoided through consistent crop rotation.

Eggplants can sometimes be seriously affected by aphids and mites. A range of organic sprays, such as Eco Neem, are suitable for controlling most insect pests on eggplants.

Growing Eggplant in Containers

Perfect for containers, these frost sensitive perennial vegetables can be relocated around the garden as winds, unseasonably cool weather and frosts are predicted, to keep them growing and producing for years.

If growing in pots, select a large pot, as you would for a tomato, and stake at planting. Always use a premium potting mix and water once or twice a day during the growing season. Apply a liquid fertilizer every fortnight and harvest fruits as soon as they ripen to encourage further fruiting.

Harvesting

Individual fruit should be harvested as soon as they are ready for use in the kitchen for maximum production. Eggplants are ready to pick when the surface of the fruit becomes somewhat soft to the touch and is readily indented when light pressure is applied. Don’t leave harvesting until too late because too many fruits left on the plant will prevent new fruit from setting.

Seed saving

Seed Longevity: 4 years

Isolation Distance: 500m

How to Save Seed: Eggplants grown for seed are left on the vine much longer than those grown for the kitchen. They will move past their glossy harvest colour, and become dull, less appealing and be softer to the touch, but don’t let them go too far – if they start to rot, you will not be able to save the seed.

Commercially, seed is wet processed, which involves mixing with water, blending (carefully) and extracting the seed. However, at home, it can be as simple as slicing the eggplant open and using a cake tester, skewer or even toothpick to remove the seeds. Seeds should be dried on paper towel for several weeks before placing in an envelope for storage. Keep in a dry, cool place for sowing next year. 

Tips and Tricks for Success

• if you live in more temperate regions of the continent, eggplants exist as perennials (provided they are protected from frosts), and once established will be productive for many seasons.
• don’t mulch eggplants until the warm weather arrives and the soil is above 20 degree C consistently.