Planting, Growing, and Harvesting Eggplants
Eggplants—also known as aubergines or brinjals—are warm-weather vegetables that are harvested in mid- to late summer. Eggplant tastes best when harvested young. See more about growing and harvesting these lovely deep purple vegetables—one of our favorites on the grill!
Eggplant (Solanum melongena) grows wild in its homeland of South Asia as a perennial plant, though these warm-season vegetables are treated by most gardeners as annuals. Given their tropical and subtropical heritage, eggplants do require relatively high temperatures, similar to tomatoes and peppers (which, like eggplants, are in the Nightshade family). They grow fastest when temperatures are between 70 and 85°F (21 and 30°C)—and very slowly during cooler weather.
Like tomatoes and peppers, eggplants develop and hang from the branches of a plant that grows several feet in height.
Because they need warm soil, eggplants are usually purchased as 6- to 8-week-old transplants (or, started indoors about two months in advance) to get a head start. Raised beds enriched with composted manure are an ideal growing place for eggplants because the soil warms more quickly. Eggplants are also great for containers and make lovely ornamental borders. In fact, there are quite a few ornamental eggplant varieties available today, whose inedible fruit have attractive variegated patterns.
Though eggplants are usually a beautiful dark purple color, their color can vary, and so can the size and shape—from small- to large-fruited.
When to Plant Eggplant
- Start seeds indoors in flats or peat pots 8–9 weeks prior to the last spring frost date. Seeds germinate quickly at temperatures between 70 to 90°F. Alternatively, buy 6- to 8-week-old nursery transplants just before planting.
- Do not plant eggplant transplants into the garden until after the last threat of frost.
- If purchasing transplants: Buy high-quality specimens. Do not purchase tall, spindly plants or young plants that have blossoms or you will have a lower yield.
Choosing and Preparing a Planting Site
- Choose a very sunny spot for the best results.
- Eggplant grows best in a well-drained sandy loam or loam soil, fairly high in organic matter.
- Soil pH should be between 5.8 and 6.5 for best growth.
- Use a covering of black plastic mulch to warm soils before setting out transplants.
- Eggplant requires moderate amounts of fertilizer. Mix 1 inch or so of well-rotted manure or a general fertilizer such as 5-10-10 throughout the planting bed about a week before planting. (Apply 2 to 3 pounds per 100 square feet. Or, apply 1¼ pounds of 5-10-10 per 10 feet of row when the row spacing is 4 feet.)
- If you’re growing eggplant in pots, use a dark-colored container that will absorb more sunlight. Each plant needs five-gallon (or, larger) pots and should be placed in full sun and outdoors so it can be pollinated. Use a premium potting mix to avoid disease.
How to Plant Eggplant
- Stake the plants right away (just an inch or two from the plant) to provide support as they climb and to avoid disturbing the soil later.
- If you live in a cold climate, consider using row covers to keep the eggplants warm and sheltered. Open the ends of the row covers on warm days so that the bees may pollinate.
- If transplanting, set 3- to 4-inch tall seedlings 2 to 2½ feet apart in rows that are 3 to 4 feet apart.
- After planting, water well. Add a layer of mulch to retain moisture and suppress weeds.
How to Grow Eggplant
- Eggplant will fall over once loaded with fruit! Be sure to stake tall plants or use a cage to keep the plants upright. If growing eggplant in containers, stake the stems before the fruit forms.
- For bigger fruits, restrict to five or six per plant.
- Pinch out the terminal growing points for a bushier plant.
- Water well to moisten the soil to a depth of at least 6 inches so the soil is moist but never soggy. Consistent watering is best, and a soaker hose or drip system at ground level is ideal.
- The critical period for moisture is during fruit set and fruit development. Mulching can help to provide uniform moisture, conserve water and reduce weeds.
- Apply a balanced fertilizer twice during the growing season. Side-dress when the first fruits are about the size of a quarter, using 3 ounces of calcium nitrate per 10 feet of row. Sidedress again in about two to three weeks.
- Note: Too much nitrogen may cause excessive vegetative growth. If you are using plastic mulch, apply fertilizer through drip irrigation, or apply fertilizer to the side of the row.
Here are some of the more common eggplant pests, diseases, and problems.
- Flea beetles are probably the most common pest, but a healthy eggplant should be able to withstand damage from their tiny holes. Damage is usually serious only on young seedlings. Grow plants under row covers until they are large enough to tolerate leaf damage. Remove garden debris in the fall to remove any overwintering beetles.
- Powdery Mildew can affect eggplant. This appears as white, powdery spots on the leaves which may turn yellow and die. The best method of control is prevention. Planting resistant varieties when available, planting in full sun, and provide good air circulation. Water at the soil level, not on the leaves.
- Tomato Hornworms are sometimes an issue as are Colorado potato beetles, lace bugs, and mites.
- If the flowers on your eggplants form but then fall off, or if fruit does not develop, the most likely problem is that the temperatures are too cold.
- If the fruits are small and not growing, it’s also probably too cold. Eggplants like it hot! Daytime temperatures need to be 80° to 90° F and night time temperatures should not go below 60° to 65° F or their grow is very slow to stalled. Wait for warmer temperatures; you may have to replant, depending on the variety.
- Strangely-shaped eggplant are the result of inconsistent watering or low moisture.
The standard eggplant produces egg-shaped, glossy, purple-black fruit.
- ‘Black Beauty’ is the traditional eggplant size. One plant produces 4 to 6 large rounded fruit. Other regular types include ‘Black Magic’, ‘Purple Rain’, and ‘Early Bird’.
- ‘Black Bell’: classic oval to round, 6-inch, purple/black fruit; disease-resistant
- ‘Dusky’: classic pear-shaped, 6- to 7-inch, glossy purple/black fruit; excellent flavor; disease-resistant
Other interesting eggplant varieties include:
- ‘Applegreen’: oval, 5- to 6-inch, tender, pale green fruit
- ‘Bambino’: oval, walnut-size, purple/black fruit; 1 1/2-foot-tall plants
- ‘Casper’: cylindrical, 6-inch, snow-white fruit; mushroom flavor
- ‘Cloud Nine’: teardrop-shaped, 7-inch, white fruit; disease-resistant
- ‘Kermit’: Thai type; round; 2-inch, green fruit with white-striped shoulder
- ‘Rosita’: pear-shaped, 6- to 8-inch, rose-pink fruit; sweet flavor
The long, slender Japanese eggplant has a thinner skin and more delicate flavor.
- ‘Ichiban’: 10- to 12-inch, slim, purple/black fruit; bears until frost. Expect a dozen or more fruit from one plant.
- ‘Little Fingers’: finger-sized purple/black fruit; good for containers. Small-fruited varieties tend to be especially heavy bearers.
Ornamental varieties are edible, but have poor eating quality.
- ‘Easter Egg’ is an ornamental eggplant, usually white in color. (Not edible.)
How to Harvest Eggplant
- Harvest eggplant 65 to 80 days after transplanting, depending on the variety. When starting from seed, expect 100 to 120 days to maturity. July, August, and September (even into October) are all harvest months for eggplant, depending on where you live and the variety you planted.
- Don’t wait too long to harvest! Eggplant tastes best when harvested young. Then, the plant’s energy will go into producing new fruit. If you harvest early and often, the plant will be quite prolific. Once ready, check on your eggplants every 2 to 3 days.
- The best way to gauge the time to harvest: Fruits are ripe when their skin first fails to rebound to fingernail pressure. Harvesting is a bit of an art; fruits can taste bitter if picked when underripe or overripe. The skin of the fruit should look glossy and unwrinkled and have a uniform color. If you cut the eggplant open, the seeds should be soft but formed. If the skin looks faded and the seeds inside are dark and hard, the fruit will taste bitter.
- Japanese eggplant may be ready to harvest when the size of a finger or hot dog.
- When harvesting, do not pull the fruit (as it won’t come off). Cut the fruit off with a sharp knife (the stem is tough) close to the stem above the green cap (calyx) on the top, leaving about an inch of it attached. The calyx can be prickly, so gloves are helpful.
- You can cut these plants back like peppers if your season is long enough for a second crop.
How to Store Eggplant
- Store eggplant in the refrigerator. The optimal conditions for storage are temperatures of 45 to 50 °F and 90-percent relative humidity for one week.
- Do not wash or cut in advance to avoid damaging the skin, which will quickly perish if exposed.
- To avoid discoloring of eggplant after cutting open for cooking or grilling, use a marinade with salt, vinegar, and/or lemon juice.
- At one time, it was fashionable for women to use a black dye to stain their teeth a gun-metal gray. The dye probably came from the same dark purple eggplant we see in the marketplace today.
- Eggplant is excellent grilled, roasted, breaded, fried, or baked! The thinner varieties (‘Ichiban’) are more ideal for grilling and roasting and the traditional varieties (Black Beauty) are great breaded or fried; the round fruit is also good as a “boat” for stuffing.
- Use a stainless steel knife (not steel) to cut eggplant or it will discolor.
- If your eggplant is oversize, the skin may be too tough to eat. Peel before cooking or bake the eggplant and then scoop out the flesh. If you’re baking eggplant, first pierce the skin a few times to allow steam to escape.
- Many Italians will tenderize an eggplant so it’s less bitter. Slice, sprinkle with salt, and allow it to rest for about 30 minutes.