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University of Rhode Island GreenShare Factsheets


Eggplants

 

History and Taxonomy:

The eggplant is probably a native of India, and has been cultivated for a long time. It is a member of the nightshade family, making it a close relative of the tomato, pepper and potato.

Climate:

The eggplant is a very tender plant, requiring a long, warm season for successful production. The plants are killed by light frost and are injured by long periods of chilly, frostless weather. Plants should not be set out until all danger of frost has passed.

Fertilizer and Lime:

Lime and fertilizer applications are best based on a soil test. In general, two pounds each of actual nitrogen, phosphorus (P2O5) and potash (K2O) per 1,000 square feet of garden space is adequate. An additional application of one pound of actual nitrogen per 1,000 sq. ft. after the fruit has set may be helpful to maintain plant development. Apply lime only if indicated by soil test results; pH should be maintained between 6.0 and 6.8.

Culture:

The use of plastic mulch can increase the yield of eggplant by helping to warm the soil, by conserving moisture and by controlling weeds. Plants may be planted in staggered double rows on each strip of plastic. Place the plastic on 5 foot centers and allow 18 inches between plants in each of the staggered rows. Because of the need for a long, warm growing season, it is best to use transplants. These may be purchased or started in peat pots or pellets 8 to10 weeks before the anticipated planting time.

Insects, Mites and Diseases:

Insect and mite pests of eggplant include flea beetles, Colorado potato beetle, aphids and spider mites. Potato flea beetles eat small holes in leaves and can be particularly serious on small plants. Colorado potato beetle adults and larvae feed on eggplant leaves and can completely defoliate small plants if not controlled. See GreenShare Factsheets on these insect pests for specific control recommendations.

Four-year rotations with non-related crops and the use of plants grown from disease-free seeds will help control some eggplant diseases. A particularly damaging disease in eggplant is Verticillium wilt, which can cause stunting in plants and interveinal yellowing, wilting and dying of leaves. Avoid tomatoes, potatoes, peppers, okra, raspberries or strawberries in rotation with eggplant.

Harvest:

The fruits of the eggplant are edible from the time they are one-third grown until ripe. They remain edible for several weeks after they become colored and fully-grown. Skin should be shiny; seeds inside should not be brown or hard. Harvest will continue over an extended period if the fruit are removed when they are well-colored and of adequate size.

Cut the fruits from the plants, leaving large calyx (cap) and a short piece of stem on the fruit. Plants of most cultivars have sharp spines, so care is necessary when harvesting to prevent injury.

 

Adapted from Ted W. Gastier, Ohio State University Extension, 2000


Pesticides are poisonous! Read and follow all safety precautions on labels. Handle carefully and store in original containers out of reach of children, pets or livestock. Dispose of empty containers immediately, in a safe manner and place. Pesticides should never be stored with foods or in areas where people eat.

When trade names are used for identification, no product endorsement is implied, nor is discrimination intended against similar materials. Be sure that the pesticide you intend to use is registered for the state of use.

The user of this information assumes all risk for personal injury or property damage.


For more information, call the URI CE Gardening and Food Safety Hotline at 1-800-448-1011 or (401)874-2929 from outside Rhode Island; Monday-Thursday between 9 am and 2 pm.

 

University of Rhode Island Cooperative Extension provides equal program opportunities.