Eggplant

Solanum melongena

Introduction: This subtropical species was first cultivated by the great civilizations of China and India almost 6000 years ago. It gradually moved west to the Mediterranean with early traders and has been grown in the warmer countries of Europe since at least the 16th century. It is a tender perennial, but is treated as an annual in temperate countries. It is one of the prettiest vegetables and doesn’t look out of place in the ornamental garden.

Nutritional value: The fruit are a useful source of vitamins A, C and some B’s, including folate, as well as calcium, magnesium, potassium and phosphorous. They are a very good source of various antioxidants and phytonutrients. They contain about 110 calories per pound.

Ease of growing: Eggplant can be quite slow to get going initially, but once it is established in the right growing conditions it isn’t too difficult to grow.

Crop value: Eggplant is a fairly nutritious plant, but it isn’t eaten in quantity It isn’t particularly productive or easy to grow either, so isn’t a very important crop from a food self-sufficiency standpoint.

Climate: The eggplant is of subtropical origin and needs a long (3 – 5 months), hot (70 – 90°F) growing season for best growth. It won’t grow well if it isn’t warm during the day and doesn’t like cold nights (below 70°F is cold for eggplant). However there are some varieties that do okay in cooler climates.

In cool climates it is sometimes grown in a greenhouse or tunnel cloche.

Did I mention that eggplant doesn’t like extreme heat either?

About Eggplant   Seed facts Germ temp: 60 (75 – 90) 95°F Germ time: 14 – 21 days 13 days / 68°F 8 days / 77°F 5 days / 86°F * Optimum Viability: 6 – 10 years Germination percentage: 60%+ Weeks to grow transplants: 6 – 10   Planning facts Hardiness: Tender Growing temp: 65 (70 – 85) 90°F Plants per person: 2 Plants per sq ft: ½ Plant size: 24 – 72˝ tall                    18 – 24˝ wide   Planning Start: 4 – 6 wks before last frost Plant out: 4 wks after last frost   Harvest facts Days to harvest: From seed: 100 – 150 days From transplant: 55 – 85 days Yield per plant: 4 lb (5 – 20 fruit) Yield per sq ft: ½ – 1½ lb sq ft

Soil

pH 5.5 – 6.8

Eggplant likes the same kind of soil as peppers, fertile, well-drained, deep and loose. They need a fair amount of nitrogen and moderate amounts of phosphorus and potassium (a fair amount is slightly more than a moderate amount).

Soil preparation: Incorporate 2˝ of compost or aged manure into the top 6˝ of soil. Raised beds are good as they help the soil to warm up faster.

Plastic mulch: When growing eggplant in cooler areas, some people use plastic mulch to keep the soil warmer.

Planning

Where: Eggplant needs a warm, sunny spot, sheltered from cold winds.

Eggplant is quite slow growing, so you may want to plant a fast growing intercrop (lettuce is good) in between the transplants. This may even be beneficial as it acts as a living mulch.

When: The seed must be started indoors quite early (10 – 12 weeks before setting out), so the plants have enough time to size up before transplanting time.

I must emphasize again that eggplants must have warm conditions if they are going to make much progress (80 – 90°F is ideal). 

Planting

Transplants

Eggplant is usually grown indoors and transplanted, because it needs warm conditions for germination. If you waited until the soil outdoors was warm enough (at least 60°F) before sowing seed, you could waste a lot of time.

Starting inside: Eggplants don’t like root disturbance, so are best started in cell packs or soil blocks. Plant 2 – 3 seeds per cell and when they all emerge, thin to the best one. Be careful when transplanting, as any damage will show up as poor growth and delayed fruiting.

Eggplant is one of the most temperamental of all the common crop seeds. It germinates best at higher temperatures than most crops (ideally 75 – 85°F) and even at the optimal temperature of 85°F, you should only expect about 60% of seeds to actually germinate. Soaking them overnight may speed up germination.

If your greenhouse (or other growing setup) isn’t warm enough you could try using heating cables, or simply start them indoors somewhere really warm. Just be sure to put them out in bright light as soon as they start to germinate.

For most rapid growth you should feed the seedlings twice a week with a dilute liquid kelp (use double the recommended quantity of water).

When your seedlings have 2 sets of true leaves you should prick them out into individual 4˝ pots.

Hardening off: By the time it is warm enough in spring to plant your eggplants outside, it will be pretty hot in the greenhouse. To avoid any kind of transplant shock, you should harden off the plants to get them accustomed to the cooler conditions outside. Do this slowly over a week, by reducing the amount of water they get and by leaving them outside for longer periods each day.

Hardening off isn’t necessary in warm summer weather, but it doesn’t hurt to keep them outside in the shade for a few days before planting out.

Buying plants: Because eggplants are so slow to start, many people prefer to buy their plants. The only drawback to this is that you have a lot less weird and wonderful varieties to choose from. When buying plants look for stocky ones that aren’t rootbound, don’t have any flowers or fruit and look deep green and healthy (with no signs of disease, pests or deficiency).

Planting out: Eggplants can’t tolerate cold weather, so they are among the last plants to go outside in spring (usually a couple of weeks after tomato). The soil temperature should be at least 60°F and the air temperature at least 70°F. It is possible to set them out earlier, if you warm the soil with black plastic or cloches (and then protect them with cloches).

You don’t usually need many eggplants, so you can take special care when planting them. Make a fairly big hole, throw in a couple of handfuls of compost and a handful of organic fertilizer mix and then plant the seedlings up to their first true leaves. Water straight after planting of course.

Direct sowing: If you have a very long growing season you could start the seed outdoors. The best way to do this is to plant them in a nursery bed (a small area specifically designated for growing seedlings) and later transplant them to their final position.

Spacing:

Beds: Put transplants 18 – 24˝ apart in the intensive beds.

Rows: Space them 18 – 24˝ apart in the rows, with 24 – 36˝ between the rows.

Care

Weeds: Eggplants are quite shallow rooted, so don’t use a hoe around them. Weed carefully by hand instead.

Water: The plants are fairly drought tolerant, but if they are to produce an abundance of tasty fruit they need plenty of water. Keep the soil evenly moist by watering deeply once or twice a week (never allow them to wilt). Don’t over-water them though, they do not like wet soil. They don’t like wet leaves either, so drip irrigation works best.

Fertilization: Once the seedlings have started growing well, give them a dose of compost tea or liquid kelp (they especially need nitrogen and potassium). Repeat this every 3 – 4 weeks for maximum production.

Mulch: In warm weather mulch is helpful to conserve soil moisture and keep down weeds (in very hot conditions it also helps to keep the soil cool). This shouldn’t be applied until the soil is warm though.

Pruning: Pinch out the growing tip when the plant is about a foot high, to make it branch and get bushier. If you want large size fruit, don’t let a plant produce more than a half dozen. Prevent this by pinching out new flowers and any lateral side shoots. You might also do this if you live in an area that is marginal for growing eggplant, so at least a few get to ripen.

Support: Eggplants are usually fairly sturdy, but the fruiting plants can get top heavy and fall over. If this starts to happen you can carefully add some bamboo cane supports (or try and coax them into a tomato cage).

An arch of concrete reinforcing wire makes a great support. While the plants are small it can be covered in plastic to keep them warm. As they get bigger they can grow through it and sprawl on top.

Protection: If a frost threatens (in spring or fall) you should protect the plants with a frost blanket, or anything else you have available.

Problems

To produce well, eggplant needs warmth, good soil and abundant moisture. They are somewhat temperamental though and sometimes you give them these things and still they don’t do well. Planting out too early is a common cause of failure; if a young plant gets severely chilled it can be permanently retarded.

If it is too cold (especially at night) or too dry, the plant may drop its flowers instead of setting fruit.

Pests: Eggplant is a member of the Solanaceae and is susceptible to the same pests as tomato and potato.

Flea beetles: These pepper the leaves with tiny holes and are a common problem. Fortunately they are not usually serious and can be ignored.

Cutworms: If these are a common problem in your area, protect your transplants with cutworm collars.

Disease: Eggplant is affected by most of the same diseases as the tomato and potato. Avoid getting the leaves wet and give the plants good air circulation.

Harvesting

When: Traditionally the fruits are harvested just as they reach full size, while their skin is still shiny. If the skin has turned dull, the seeds are ripening (they turn brown) and it is too old.

Small: In Asia they often pick the fruit while it is the size of an egg, or only slightly larger. These young fruit are tastier and have a better texture than older ones. Picking smaller fruit also increases the harvest, as a plant can produce many more of them. It also lengthens the harvest, as they will produce over a longer period of time.

How: Cut the fruit from the plant with a knife or secateurs, without pulling on the plant too much. Leave an inch of stem attached to the fruit.

Storage: Eggplant should be treated like a tomato, which means picked when ripe and used immediately (it doesn’t mean eat them raw). Keep them at a cool room temperature (not in the fridge) and they should be good for a week or so. For longer term storage they fruits can be cut up and frozen.

Seed saving: The plants are generally self-pollinated, but some cross pollination by insects also occurs. To keep a variety pure only one variety should be grown at one time, or it should be isolated by at least 50 feet. To ensure genetic variability, you should save the seed from at least 6 plants.

To get ripe seed, you need to let a fruit ripen completely. Separate the seed from the fruit by grating the seed bearing flesh and then mashing it in water. The seed is then dried for storage. Eggplant seed is quite long lived if stored properly and may last for up to ten years.

Unusual growing ideas

Ornamental: With its mauve flowers and shiny fruits, eggplant is one of the most attractive vegetables and can easily blend into the ornamental garden.

Containers: If you live in a less than ideal climate you might try growing eggplant in a container. You can put it outside when it is warm and bring it indoors if it gets too cold. It also helps that the soil in a pot will get warmer than it would in the ground. It should be a fairly big pot (at least 12˝ deep) though and you must take care to keep the soil moist.

Tunnels: In cooler climates eggplant may be grown in plastic tunnels to give it additional heat. Open these up whenever it is warm enough, so bees can pollinate the flowers.

Varieties

If you don’t have the ideal climate for eggplants you should choose an early maturing variety. Most of the eggplant varieties that are available are of two main types.

American / European: These are the eggplants you see in stores, fairly big and somewhat pear shaped with shiny purple skin. There are also some less common white fruited varieties that are the reason this plant is known as eggplant.

Black Beauty – An old favorite.

Casper – A beautiful and tasty white variety.

Asian: The small Asian eggplants are considered to be tastier than the larger western varieties. They can also be more productive, as the fruits are picked when smaller (so more will form.) They are often more attractive too.

This is another crop where F1 hybrids are taking over the seed catalogs. However there are still many fantastically multi-colored (orange, white, green, yellow, purple) open pollinated heirloom varieties from Asia. These are becoming much more widely available and can be quite spectacular. In fact they are some of the prettiest vegetables you will ever see. I make no claim to be an eggplant expert, but these varieties are highly rated:

Ichiban – Long purple fruit, does well in cooler areas.

Little Fingers – Small purple fruit, not much bigger than your fingers.

Millionaire – Purple fruit, very early (54 days from transplanting).

Orient express F1– Does well in cooler areas. Fast maturing (6o days from transplanting).

Rosa Bianca – Italian heirloom, medium size, purple fruit (80 days from transplanting).

Rosita – Pink / purple fruit (80 days from transplanting)

Thai Green – Long narrow green fruit, vigorous (80 days from transplanting)

Fairytale F1 – One of best tasting varieties, white / purple fruit.

Kitchen use

Probably more than any other common vegetable, cooking and recipe is all important with eggplant. A badly cooked eggplant is almost inedible, while a well-cooked one is absolutely delicious.

Eggplants have a natural affinity with barbecues and are an excellent meat substitute.

Garlic, basil and marjoram all go well with eggplant.

Eggplant with Garlic   3 or 4 oriental eggplants chopped into 1˝ cubes 2 cloves garlic 4 green onions chopped 1 tsp chopped fresh ginger 1 tsp chili sauce 1 tsp wine vinegar 1 tsp sugar ½ tsp ground black pepper 1 tbsp cornstarch 4 tbsp water 4 tbsp soy sauce 1 tbsp sesame oil   Mix the sugar, soy sauce, chili sauce and pepper in a bowl. In another bowl mix cornstarch and water. Saute the garlic, 2 green onions and ginger in a little oil for several minutes. Add the eggplant and soy sauce mix and simmer 15 minutes. Finally add the cornstarch and rest of the onions and cook for a few minutes more.