Eggplants are a member of the nightshade family, which includes tomatoes, peppers and potatoes. Eggplant comes in many shapes and colors, the most common being dark purple. White-skinned varieties such as Casper offer a nice change from the typical purple. Eggplant is most frequently started indoors from seed.
Two months before the final spring frost date, fill each cell of a plastic seed tray with sterile seed-starting mix. Moisten the mix with water and place two eggplant seeds in each cell. Cover the seeds with 1/8" of starting mix and moisten the soil again. Place the clear plastic cover over the tray to keep the humidity level high.
For eggplant seeds to germinate well, the soil temperature should be kept between 75 and 85 degrees Fahrenheit. After the seeds germinate, use a grow light for 16 hours a day to nurture the seedlings. A sunny south-facing window can also be used. When the seedlings develop their first true leaves, feed with all-purpose water-soluble fertilizer.
Seedlings that have been grown indoors need to be gradually introduced to outdoor conditions. Place the tender seedlings outside in a shady spot for a few hours and then bring them back inside. Each day for the next week leave them outside a little bit longer and expose them to a bit more sun.
When the plants are about eight weeks old and well hardened off, they are ready to be transplanted in the garden. Work the appropriate amount of 5-10-10 fertilizer into the garden before planting. Very carefully remove a seedling from its cell and place it in a hole at the same depth it was in the tray. Space the plants 18" apart in rows 24" apart. Water well.
Eggplants are best when harvested at one-third to one-half their mature size. To test whether the fruit is ready for harvest, gently press the skin with a finger. If the spot stays indented and doesn't spring right back, the eggplant is perfect for picking. Cut the fruit from the vine with a pair of pruning shears.