By Les Harrison, UF/IFAS Wakulla County Extension Director, and Gohar Umar, FAMU Horticulture Specialist.
The summer temperatures have transformed the vegetable gardens of Wakulla County. The daily 90 degree plus thermometer readings and the typical summer humidity have wilted many spring garden vegetables.
One heat hardy exception is the eggplant (Solanum melongena). This member of the nightshade family, which also includes tomatoes, requires the heat to thrive and produce.
This vegetable is called “eggplant” because the original plant produced small, oval-shaped white fruit which resembled a chicken or duck’s egg. Eggplant is native to India and Pakistan, and it was first cultivated more than 4,000 years ago.
Ancient Chinese records indicate eggplant was grown in China as early as the first century BC, and crossbred varieties with different shapes and colors were propagated. The migration of the eggplant continued toward the Middle East and westward to Egypt during the 9th to 12th centuries. The Moors introduced eggplant to Spain, and the fruit became popular in Europe.
As the Spanish were exploring the globe, they took the eggplant along to South America around 1650. In 1806, Thomas Jefferson, who was well-known for his promotion of horticulture, introduced the eggplant to the United States after receiving the fruit from a friend in France.
As a member of the same plant family as tomatoes and peppers, eggplants are susceptible to many of the same diseases which afflict these garden staples. Viruses such as tobacco mosaic virus and tomato mosaic virus can be a common problem.
Typically, these viral infections cause stunted plants, fruit and leaf malformation, mottling, and leaf mosaics. Immediate removal of infected plants and control of weeds and insects is critical to prevent the spread of these diseases.
Eggplant does best on well-drained, fertile, sandy-loam soils with a pH of 6.0 to 6.5. Poorly drained soils may result in slow plant growth, reduced root systems, and low yields.
Eggplant production practices are similar to those of tomato production. Use of mulch will help keep the soil at the correct moisture level and suppress weeds.
Eggplants require a long warm growing season of usually of 14 to 16 weeks. Chilly temperatures below 50°F will damage this cold sensitive vegetable and eliminate its yield.
The best temperatures are between 80°F and 90°F during the day, and 70°F–80°F during the night. Plant growth is noticeably slowed at temperatures below 60°F.
Soil temperature below 60°F restricts eggplant seed germination. If planting early in the north Florida spring, it is best to use transplants started in a greenhouse.
Modern hybrid eggplants are the result of two genetically different purebred varieties. The cultivars were selected for certain characteristics, such as resistance to viruses and other desirable characteristics.
Heirlooms eggplants are old cultivars generated by handing down seeds from generation to generation. In order to be considered an heirloom, the eggplant variety must be true-to-type, open-pollinated, and it must have been in use for at least 50 years.
Pollination is by insects, birds, wind, or any other natural means, and the following generation of eggplants will be identical to the parent plant. Although heirlooms are not selected for traits such as disease resistance, they are usually selected for superior flavor, unusual color, and texture.
Because heirlooms are true-to-type, they will have consistent traits from one generation to the next. The seeds can be saved and regrown the following year or shared with friends.
Hybrid or heirloom, eggplants are a productive summer vegetable in Wakulla County.