- Cornell University - Explore Cornell - Home Gardening - Vegetable Growing Guides - Growing Guide
- Michigan State University - How to Grow Eggplant - MSU Extension
- University of Florida - Eggplant - Gardening Solutions - University of Florida, Institute of Food and Agricultural Sciences
- University of Minnesota - Growing eggplant in home gardens | UMN Extension
Eggplant is a member of the nightshade family, like its relatives tomatoes and peppers. Eggplant is also known as aubergine. Purple is the most common color, although green and white-skinned varieties are also popular. Native to India and Southeast Asia, and cultivated there for thousands of years, the plant has been grown in the area around the Mediterranean Sea for a very long time and has been grown in Spain since the early middle ages.
Eggplant is a member of the nightshade family, like its relatives tomatoes and peppers. Eggplant is also known as aubergine. Purple is the most common color, although green and white-skinned varieties are also popular. Native to India and Southeast Asia, and cultivated there for thousands of years, the plant has been grown in the area around the Mediterranean Sea for a very long time and has been grown in Spain since the early middle ages. There is a huge variety of recipes for different types of eggplant. A favorite dish is Baba Ghanoush, though it is also roasted, stir-fried, baked, and grilled in all sorts of ways.
Eggplant is mild tasting. It’s slightly sweet and slightly bitter, but it takes on the flavor of anything it is cooked with. Common varieties are long and purple, looking like a dark zucchini or squash, and resemble them in the texture, and general flavor, despite being a different type of vegetable. The most recognizable might be the classic Black Beauty, a longish, somewhat rounded dark purple eggplant, seen in the grocery store and grown in gardens all over. Some eggplant types are round, like the larger Barbarella, or smaller varieties like the Thai Kermit (green) or Lavender Frog Egg (purple and white). Asian varieties are usually more tender and lack the tougher skins of some European eggplants.
Eggplants are nutritious! They are an especially good source of vitamins A, C, and K, as well as potassium, calcium, and iron. They are very high in fiber, and antioxidants, and are considered an excellent source of vitamin B1, B6, magnesium, and phosphorus. Eggplants also provide polyphenols, which can aid in lowering blood sugar in some cases.
- Eggplant (Solanum melongena)
- Perennial, grown usually as an annual
- Full sun
- Soil should be somewhat acidic (5.5 to 6.5 pH)
- Well-drained rich warm soil
- Garden planting:
Start indoors 3-4 weeks before the last frost
Transplant outdoors 4-6 weeks after the last frost.
Plants 24 inches apart
Garden rows 30-36 inches apart
- Container planting:
Single plants in 18″ deep and 18″
Multiple plants spaced 10″ apart in 20” wide pots
- Water thoroughly at least 1 inch per week
- Climate Zones 5-12
Eggplants grow fairly large, and they are warm-weather plants. It’s important that the soil be warm, 55°F minimum, but hopefully near 65°F. The soil should be well-drained. This plant needs to create a substantial root system, so clay soils and sandy soils should be amended with compost or garden soil. For best results, reference your growing zone and the Hortisketch planting information.
Start the seeds indoors up to a month before the last frost. They should be planted ½ inch deep, with two seeds per container. A heat mat improves and accelerates germination. Once the seeds sprout, and each has leaves, thin them by removing the smallest plant in each container, leaving one seedling in each. Plant the seedlings in the garden a month to a month and a half after the last frost, when they are about 4 inches tall.
Due to their size, eggplants do need some space. Each plant should be approximately two feet apart, or even a little more if desired. Stake them or use a small trellis (or a tomato cage), they will need some support. If staking, put the stake in when you plant the eggplant, to avoid disturbing the root system by putting it in after it’s big enough to need it.
As already stated, this is a warm-weather plant. The ideal temperature is between 70°F and 85°F. Sustained temperatures above 95°F and below 60°F can cause the plant to stop fruiting, and colder temperatures can stunt its growth. Full sun is needed, at least 6 hours of full sunlight on most days is best, more is better. Plant them in a south-facing part of your garden. Being careful about the temperature and sun will produce large eggplants for your table.
Container gardening is a great option for eggplants, especially if there is concern about the climate, as this gives you some more control over the conditions. Large containers are absolutely necessary to accommodate the root system. In cooler climates, dark containers will absorb more heat from the sunlight and can help keep the soil warmer. A large container is absolutely necessary, at least a 5-gallon container, meaning a 18-inch pot. It’s best to keep one plant per container. Multiple plants can be put into very large containers, two in a 20-inch container, but that is harder to manage unless you plan things carefully. A tomato cage is a good idea to provide support for eggplant in this type of pot.
Adding a slow-release fertilizer at the time of planting is a good idea for both eggplants in the ground and in containers. For garden eggplants, that may be enough, but adding this kind of food every two to three weeks may be needed for potted eggplants. This allows for better growth since container plants don’t have access to the full range of nutrients in garden soil. Watering consistently is also important for any eggplant. Make sure that they get at least one deep watering at least once per week. Allow the plant to get a little dry between waterings.
Green beans and peas, especially bush beans, are good companion plants for eggplant, since they protect this fruit from potato beetles, and add nitrogen to the soil. Other plants from the nightshade family like peppers and tomatoes also make good companion plants, since they have the same nutrient requirements and share many of the same pests. This can allow for a single treatment if pests or disease become a problem. Plants like dill and chives and even dandelions elsewhere in the garden will help attract ladybugs which greatly help against pests.
The flea beetle is the biggest pest concern, especially for younger plants, which need their leaves to continue growing. Treatment with neem oil can help a great deal with this. Other insects that are a concern include the already mentioned potato beetles, as well as caterpillars, aphids, spider mites, and the growing problem of stink bugs. At the risk of being repetitive, attracting ladybugs is one of the best ways to deter aphids, stink bugs, flea beetles, and other pests.
Disease can also be an issue. Bacterial wilt, damping off, leaf spot, and fusarium wilt are all problems. For any of these fungal or bacterial infections, it’s best to remove the plant completely and dispose of it away from your garden. There are no treatments for these, once infected. Prevention is the best cure, so avoid overwatering, ensure good drainage, and rotate the crops to prevent reinfection. For biological control, potential candidates are DoubleNickel55 or Cease.
When ready to harvest, the eggplant fruit will be glossy and firm. Press your thumb into the eggplant, if it springs back quickly, or if it’s hard, it’s unripe. If it leaves an impression on the fruit, it’s overripe. Unripe and overripe eggplant are both more bitter than eggplant harvested at the right time. It will be smaller than the eggplants you see in the store, when ready to pick. Cut the fruit from the plant, and leave about an inch of stem on the fruit. They are best stored in cool but not cold temperatures.