Eggplants need warmth throughout the growing season to do well. Eggplants need soil temperatures above 70° and daytime air temperatures above 70°. Eggplant seeds will not germinate in cool soil. Nighttime temperatures should be above 60°. Eggplants have a growing season of 100-150 days in ideal conditions. Although they do best in warm climates, they can be grown in northern climates if mulches, row covers, or hot houses are used.
Eggplants prefer well-drained sandy loam of pH 5.5 to 6.5 with high organic matter content. Eggplants need a moderate amount of nitrogen and high amounts of phosphorus and potassium. Eggplants like temperatures between 80° and 90° for optimal growth.
Eggplants are typically spaced 18-24" apart in rows 30-36" wide. Rows should be 30-36" apart. Don't crowd eggplants, they will do better with a little extra room. They can be staked and supported like tomatoes to ensure proper air circulation.
In hot climates with long growing seasons, eggplants can be direct seeded in rows 1/2" deep and 18-24" apart after soil and air temperatures have warmed. Keep seeds evenly moist. For best results soil temperature should be 80°-90°.
Seeding For Transplants
Eggplants are most commonly started indoors or in a greenhouse. Soak seeds in water overnight to encourage germination. Eggplants are very sensitive to transplant shock so use peat pots that can be planted directly into the ground. Plant seeds singly in peat pots 1/4" deep and grow under lights if available. Use bottom heat to keep the soil warm, optimal soil temperature for germination is 85°. Air temperature should be above 70° during the day and above 60° at night.
These seeds germinate best in soils around 75°F - 90°F.
Germination will take 7-10 days.
Transplanting Into the Garden
Eggplants are very sensitive to transplant shock and benefit from several days of hardening off. About one week before transplanting, gradually expose them to the outside air by bringing the eggplant starts outside during the day and inside at night. Gradually increase the exposure each day (weather permitting, of course) until the plants are out until after dark.
When the eggplants are ready to be transplanted carefully place the peat pots in moist garden soil. In the north, use mulch to keep the soil warm and row covers over the plants to keep them warm at night.
Eggplants need regular watering, but they do not like to be kept too moist. Water eggplants to maintain uniform moisture. Water plants in the morning so the leaves are not damp through the night.
Eggplants are ready to harvest when the skin takes on a high gloss, at a third to half their mature size. To test for readiness, press the skin with your finger. If the indent does not spring back, it is ready to harvest. Fruits with dark brown seeds inside are past their prime.
Harvest eggplants when they are tender by clipping the fruit off with garden shears. Harvesting fruits regularly stimulates further production.
Be careful not to damage the skin of eggplants. Wash and dry eggplants thoroughly.
Eggplants are not suited to long-term storage but they can be kept 1-2 weeks at 55° with a relative humidity of 85%-90%.
Eggplants are sensitive to ethylene gas so do not store them with fruits and vegetables that produce ethylene gas.
Flea beetles, aphids, potato beetles
Use black plastic to increase the yield of eggplant by helping to warm the soil, conserve moisture, and control weeds.
Rotate crops to prevent diseases.
Insects love eggplant. Use row or mesh covers help alleviate this problem. If covers are used, however, the flowers must be pollinated by hand.
Oregon State University, "Eggplant, Commercial Vegetable Production Guide", Last modified 2002-12-27, Oregon State University, http:www.orst.edu/Dept/NWREC/eggplant.html, Accessed 2003-05-16
Bradley, F. M. and Ellis, B. W.(Ed.). (1992), Rodale's All-New Encyclopedia of Organic Gardening: The Indispensable Resource for Every Gardener, Emmaus, Pennsylvania: Rodale Press.
Smith, E.C. (2000), The vegetable gardener's bible: discover Ed's high yield W-O-R-D system for all North American gardening regions., Storey Books: Pownal, VT.