Vegetable · Solanaceae
Eggplant
Solanum melongena
Feed it heat, full sun, and steady water, and eggplant hangs heavy with glossy, deep-colored fruit.
Full sun
Every 3–7 days
61–90°F · 16–32°C
65–80 days
Overview
Eggplant is a heat-loving nightshade hung with glossy, meaty fruit that catches the light on its taut skin. The plant carries broad leaves on sturdy stems, and it traces back to South and East Asia, where it has been cooked for centuries, from Italian parmigiana to grilled Japanese nasu. Gardeners know it as aubergine or brinjal, and it stands in the same family as tomatoes, peppers, and potatoes.
Among warm-season vegetables, eggplant asks the most patience before it shows its fruit. It needs a long, warm run to crop well, so most growers start it indoors and set it out only once the nights turn dependable. Through that warmth the plant keeps hanging out new blossoms and fruit until the cold finally stops it.
The fruit takes far more forms than the supermarket suggests. There are the large purple-black ovals with a near-mirror shine, the long and slender Asian types, and the pale white-skinned varieties. Caught early, while the skin still gleams, the flesh inside stays sweet rather than turning bitter.
Care
The short version: full sun and warm soil, with steady, even moisture of about an inch of water a week, set in rich, well drained ground, given little nitrogen, and picked while the skin still holds its glossy shine.
Light
Eggplant wants full sun on its broad leaves, the more direct hours the better. It holds no real shade tolerance, and a plant kept in dim light stretches leggy and pale, setting little fruit.
Water
Aim for steady, even moisture, about an inch of water a week, rather than a swing from dry to soaked. Uneven watering turns the glossy fruit bitter and thins the crop. Water reaches the plant best at the base, away from the leaves, which keeps disease off the foliage.
Soil
Plant it in fertile, well drained loam rich with organic matter. Eggplant takes a wide pH band from 5.5 to 7.5, so most decent garden soil suits its roots.
Temperature
This is a true warm-season crop, happiest between 61°F and 90°F (16°C to 32°C). Cold checks its growth hard, and nights below 50°F (10°C) drop the flowers from their stems before fruit can set.
Humidity
Ordinary outdoor humidity suits it, so there is no number to chase. Good airflow matters more, since crowded, damp leaves are where fungal trouble takes hold.
Feeding
Side-dress with a nitrogen source such as calcium nitrate three to four weeks after planting, then again later in the season. Keep the nitrogen light, since too much grows a thick, leafy plant that delays the fruit.
Pruning
Eggplant rarely needs pruning. Damaged or diseased leaves come off, and a stake or cage holds the taller, heavily fruiting plants upright so the hanging fruit stays off the ground.
Size & spacing
Plants stand 2 to 4 feet (60 to 120 cm) tall and spread 18 to 30 inches (45 to 75 cm) across, a bushy, leafy frame. Set well apart, they let air move freely and let the fruit hang clear of the soil.
When to plant
Eggplant runs on heat and has no tolerance for cold. The seeds start indoors about 8 weeks before the last frost, the plants move out only once nights hold above 50°F (10°C), and the first glossy fruit colors up from midsummer onward, roughly 65 to 80 days after transplanting.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: About 8 weeks before the last spring frost
- Plant: After all danger of frost, when nighttime temperatures stay consistently above 50°F (10°C)
- Harvest: Harvest 65 to 80 days after transplanting, when fruit is large, glossy, and uniformly colored
Hardiness
USDA hardiness zones: 4–12
Temperature: down to -34°C
Troubleshooting
Eggplant shows its troubles right on the surface, in pocked leaves, wilting stems, and dull or pitted fruit, and the warm, humid weather it loves draws pests and disease alike. A close look at the plant catches the early marks before they spread. Match what you see below, then act while it still helps.
Plant wilting and yellowing with brown streaks inside the stem
A plant going limp with yellowing lower leaves points to verticillium wilt, a soilborne fungus that clogs it from within and worsens as fruit forms. A stem sliced near the base shows brown streaking running through the pale inner tissue, the giveaway sign. There is no cure, so badly marked plants come out and go to the bin, never the compost, and eggplant rotates away from tomato, pepper, and potato for several years.
Fix:
- Remove and destroy severely affected plants
- Do not compost infected material
Tiny round holes peppering young leaves
Those leaves stippled with flea beetle damage show many small round pinholes, the marks of tiny dark insects that spring away when the plant is disturbed and cluster on tender transplants. Floating row covers laid over young plants keep them off, and the weeds nearby that shelter the pest are best kept down. A vigorous, well-fed plant usually grows past the early pinholing on its own.
Fix:
- Use floating row covers on young plants
- Apply labeled insecticides if infestations are heavy
- Keep plants vigorous so they outgrow early damage
Flowers forming but dropping before any fruit sets
When the blossoms open and then fall from their stems with no fruit behind them, that is blossom drop, brought on by nights below 60°F (16°C), spells of extreme heat, or too much nitrogen feeding leaves over fruit. The signs are temperature extremes around flowering and a lush, leafy plant carrying only a few blossoms. Setting transplants out once nights stay warm, and feeding to soil-test rates, holds the flowers on.
Fix:
- Transplant only after nights stay warm
- Avoid over-fertilizing with nitrogen
Fruit turning bitter on the plate
Bitter fruit follows uneven soil moisture or fruit left hanging too long, its skin gone dull and its flesh turned seedy. Fruit picked while the skin still gleams stays sweet, and steady moisture from mulch and regular watering keeps it that way. Once the shine fades and the seeds set in, the bitterness holds no matter how the fruit is cooked.
Fix:
- Maintain even soil moisture
- Harvest fruit while skin is still glossy
Toxicity
The ripe, cooked fruit is good to eat, but the rest of the plant is not. The broad green leaves, the stems, and the unripe green fruit hold a natural compound called solanine that upsets the stomach, and it is mildly toxic to cats, dogs, horses, and other animals if the foliage is eaten. Keep those green parts away from pets and curious children.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that bites into the leaves or stems may drool, vomit, or pass loose stools from the solanine in that green tissue. The glossy fruit is no worry, the foliage is.
Dogs Mild
A dog chewing the green parts can be left drooling with an upset stomach for a while. Most cases stay mild, though a large mouthful is worth a vet call.
Horses Mild
Horses grazing the leafy tops can land in colic-style stomach upset with a dull, sluggish look about them. Keep them clear of the plants and any trimmings.
Rabbits Mild
The leaves and stems carry solanine in their tissue and do not belong in a rabbit's diet. A small taste of that foliage may bring on soft stools and a poor appetite.
Livestock Mild
Cattle, goats, and sheep can take a digestive hit from grazing the green tops, so the rows and clippings are best fenced off.
Birds Mild
A bird pecking at the leaves or green fruit can end up with an unsettled gut. Backyard hens generally leave the bitter foliage alone, and trimmings do not belong near them.
People Ripe fruit safe
Ripe, cooked eggplant, with its glossy skin and soft flesh, is a kitchen staple and safe to eat. The raw leaves and stems are the part to skip, since they carry the same solanine that troubles animals.
Keep pets and children from chewing leaves, stems, or green/unripe fruit; the cooked ripe fruit is edible.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Eggplant takes on far more shapes and colors than the one form most stores sell. These are the types worth knowing by name.
Black Beauty / Italian types (e.g., Dusky, Epic)
These are the classic eggplants, hung with large, glossy purple-black oval fruit so dark it nearly mirrors the light, the shape most people picture first.
Ichiban (Asian type)
An Asian type bearing long, slender fruit sheathed in thin skin over tender, fine flesh that cooks quickly.
Casper
A specialty variety set apart by smooth, pale white skin, a striking break from the usual deep purple.
Hansel
A compact plant that hangs clusters of small, slender fruit close along its stems, which suits pots and tight beds.
Companions
Eggplant grows best beside beans and marigolds, and worst beside its nightshade cousins like potatoes, which trade the same pests and diseases back and forth.
Plant near
Beans: Listed as a beneficial companion for eggplant in extension companion-planting guidance
Marigolds: Listed as a beneficial companion; marigolds are associated with pest/nematode suppression
Keep apart
Potatoes: Listed as incompatible with eggplant; both are nightshades sharing pests and diseases
How to propagate
Eggplant starts as seed, and it needs warmth and a long head start indoors before the season turns and the young plants are ready to move.
SeedModerate
Start indoors about 8 weeks before the last frost · 6 to 8 weeks to transplant size indoors
Eggplant grows from seed started indoors about 8 weeks before the last frost. The seed needs warmth to break open, so a heat mat holding the soil around 75°F to 85°F (24°C to 29°C) coaxes it up. The seedlings take 6 to 8 weeks to thicken to transplant size, and they move outdoors only once the nights are reliably warm.
Myths
Every part of an eggplant is poisonous, so the fruit is unsafe to eat.
The solanine-type glycoalkaloids gather in the green leaves, the stems, and the unripe green fruit, not in the glossy ripe fruit that is cooked. Ripe eggplant is a safe, everyday food, eaten around the world for centuries.