Eggplants: Easy to Grow with Surprising Variety and Versatility
For many of us, the word eggplant connotes a tear-drop shaped, shiny purple vegetable that we can grill or prepare parmigiana style. In fact, there are many varieties, including some that, true to its name, are about the size, shape and color of white chicken eggs. It is truly international, called aubergine and melanzane in the Mediterranean regions and brinal in its native India and South Asia. Australians refer to them generally as eggfruit. In parts of Africa it is called garden egg. And it has as many styles of preparation as it has names.
Eggplant is a member of the Solonaceae or nightshade family, related to tomatoes, peppers, potatoes and tobacco. The plants have spiny stems and generally long, lobed leaves. Flowers range in color from white to purple and can be quite attractive, which, along with their colorful fruits, make them adaptable as annual landscape plants. Heavily laden plants may need support as fruit matures.
Botanically, eggplant is classified as a fruit, with its many small edible seeds. They are best harvested before reaching full size, both because their nicotine content adds a bitter taste to older fruits and because leaving mature fruit unpicked reduces plant productivity.
Eggplants are tropical perennials, but for most gardeners they are grown as annuals in Zones 5-12.
Eggplants love heat. Seeds germinate well between 70 and 90 degrees. A heat mat is a definite plus and a plastic cover for the seed tray can also help germination. Growing time is typically between 100 and 140 days from germination to harvest, depending on variety. Start seeds 6-8 weeks before last frost and harden plants off for a couple more weeks before transplanting. Warming soil with black plastic and/or growing in raised beds or containers can provide an earlier and smoother transition for transplants.
Outdoors they need full sun and are heavy feeders, requiring fertile, well-drained soil, high in organic matter. The pH should be slightly acid, in the 6-7 range. Plants need consistent soil moisture, about an inch of water per week. Plant 18-24” apart in rows 36” wide. As noted, they need warm temperatures with night time temps of 70º or higher. When conditions are right, harvest should begin 55-85 days from transplant. They are ready to pick when shiny and when the fruit has a little give when squeezed gently. If the skin has dulled and the seeds are dark, discard them. Because stems are tough, fruit should be cut from the plant rather than pulled off. Stems are spiny so wearing gloves may make sense.
If plants are bearing into the fall, pinch blossoms 2-4 weeks before expected frost to encourage ripening of already formed fruit.
Pest and Disease Concerns
The eggplant flea beetle is the major pest worry. It is a black oval-shaped beetle that progresses from egg through larval stage to adult in 30-45 days and typically has two generations per year in Virginia. Adults overwinter in soil and debris, emerging in late May/early June. The adults chew small holes in leaves that reduce the plant’s photosynthetic capability, thus affecting the size of individual fruits and overall yield. Plants can be protected with row covers until flowering. Insecticidal soap and spinosad can help control beetles. Pyrethroids can be employed for heavy infestations. Gardening lore says that placing onion peels around plant bases repels the beetles, but I can’t vouch for its efficacy. Unfortunately, there is no effective biological control.
The eggplant lace bug is probably the next most serious pest. It progresses from egg through 5 instars (immature stages) to adult in about 20 days and goes through 5 generations per year. Nymphs suck plant liquids from the underside of leaves, which show scorching damage before dying. Discarded skins and fecal deposits on leaf undersides are telltale signs. Ladybugs, spiders and pirate bugs are beneficial predators. Insecticidal soaps, neem oil, and pyrethrins can help if heavy infestations demand them.
The most serious disease concern is verticillium wilt, which disrupts water uptake and causes plants to wilt and eventually die. It is a good idea to look for resistant varieties if possible and definitely avoid planting eggplants where other nightshades have recently been grown.
Growing in Containers
Eggplants are readily grown in containers and can actually be displayed as ornamentals given their interesting vegetation, pretty flowers and colorful fruits. Smaller varieties are recommended for containers, which likely means starting plants from seed to have a choice of varieties beyond standard nursery offerings. Using relatively large containers can help with moisture management.
Moisture requirements dictate developing a fast-draining but moisture-retaining potting soil mix and a container with generous drainage holes. Plants are quickly damaged if they are allowed to dry out in summer heat, so consistent watering is a key to success. Verticillium wilt and flea beetle damage are less of a problem if good quality potting soil is used, a big plus. If using a sterile potting soil, mixing in compost and an all-purpose fertilizer when planting and periodically during the season is a good idea.
Eggplant is considered nutrient-dense, with an abundance of fiber, vitamins and minerals, with few calories. It is also high in an antioxidant called nasunin, which can help prevent heart disease and cancer. In the end, the way it is cooked affects its ultimate benefits, but it definitely starts out as a beneficial food source.
If you are interested in growing the large purple eggplants that we are most familiar with in the US, transplants are readily available at most nurseries and garden centers. For other types, seeds are available if you shop around. Popular early varieties include Ichiban, Dusky and Little Fingers. Mid-season varieties include Black Beauty, Classic, Ghost Twister and Neon. There is an abundance of information about the range of varieties online.
Give it a try
Growing up in an Italian family, I learned to enjoy eggplant prepared in the traditional Mediterranean ways. More recently, in travels and with the increasing diversity of restaurants and cuisines in our area, I’ve learned to love it served many different ways. And, one of these days, I’ll perfect my grilling technique as well.
In any case, eggplant is a versatile and nutritious vegetable that grows well in the Central Virginia climate, with a little care in the areas of moisture and pest management. I encourage you to give growing it a try.
Be sure to check out the recipe for Eggplant and Tomatoes with Caper-Shallot Vinaigrette in this month’s Garden Shed.
“Potatoes, Peppers and Eggplant,” Va. Coop.Ext., https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/426/426-413/426-413_pdf.pdf
“Flea Beetles Attacking Eggplant in Virginia,” Va. Coop. Ext. https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/ENTO/ento-270/ENTO-270.pdf
“Eggplant Lace Bug,” Va. Coop.Ext. https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/3104/3104-1548/3104-1548_pdf.pdf
Cornell University Growing Guide: Eggplant, http://www.gardening.cornell.edu/homegardening/scene26b5.html