How to Grow Eggplants as an Annual or Perennial

The lush, ripe fruit produced by eggplant plants is one of my favorite late summer treats.

These warm-season vegetables from the Solanaceae family have long been treasured for their pear-shaped fruit. Even their lobed leaves have a history of medicinal use, and the ancestral wild eggplant species from South Asia have developed into a bewildering array of different varieties found in grocery stores in far-flung parts of the world.

But are eggplants perennial? Can you get a favorite specimen to endure the last frost and survive to the next growing season, or are they doomed once the cool temperatures inflict their damage? When’s the best time to plant, and how do you get the best results from your eggplant fruits?

Read on to find out all of those answers and more.

Eggplant Overview

Scientific NameSolanum melongena
Common NamesEggplant, Aubergine, Brinjal, Guinea Squash
FamilySolanaceae (Nightshades)
Size and Dimensions (Mature)Up to three feet (1m ) tall, equally broad
Distinguishing FeaturesEdible fruit
In-Home PlacementVegetable garden, hydroponics setup, container garden

Are Eggplants Perennial?

eggplants hanging via plant

Eggplants are perennial, but they are more often grown as an annual crop.

In warm climates, eggplants grow as a perennial and will fruit reliably for around three years.

In cooler areas, like most of the United States, they won’t survive the winter and are best grown as an annual. They aren’t frost-hardy in any way and will die off completely once the cold weather arrives.

When to Plant Eggplant

man planting eggplant seedlings in the field

Eggplants have a long growing season and need an average of 100 to 140 days of good, warm weather to reach full maturity.

You’ll need to get them in the ground as soon as the soil temperature is warm enough. You also need average daytime soil temperatures consistently around 60 degrees  Fahrenheit before you plant.

This is typically mid to late spring after the danger of frost has passed and nighttime temperatures do not dip below freezing.

As a result, many growers start their eggplant as seedlings indoors or buy seedlings that are ready for transplant.

This gives a head-start for those of us growing in cooler climes. 

Eggplant Care and Growing Conditions

man handwatering eggplants

Fertile, Well-Draining Soil

Eggplants require fertile, well-drained soil full of organic matter, with a soil pH of between 5.5 and 7.5.

Before you plant, it’s prudent to amend the bed with lots of well-rotted manure, compost, or a phosphorus-rich fertilizer like blood meal.

The added organic material will retain water while providing good drainage, even in clay soil.

Consistent Watering

Eggplants need moist soil to provide the root system with good hydration. One to two inches of water weekly should be enough, especially if you have mulched well.

Semi-Warm Temperatures

These tropical plants love warm weather and are far more sensitive to the cold than other nightshades, like tomato plants.

Ideally, eggplants prefer daytime temperatures of around 70 to 85 degrees Fahrenheit during their growing season. 

As a warm climate crop, you can ensure good growth by keeping their roots well mulched. It’s like a thick blanket that does double duty keeping the soil moist, too.

Apply mulch once soil temperatures are consistently around 75 degrees Fahrenheit, or use black plastic to ensure warm soil.

I can’t stress how much serious damage a cold snap will do to your crops.

Frost protection measures like row covers or cold frames can help you protect against the danger of frost damage and allow you to start your growing season earlier than usual if needed.

Direct Sunlight

Eggplants need a minimum of six hours of direct sunlight each day. That said, for a good harvest, they’ll need around eight to ten hours of light.

Moderate Humidity

Atmospheric humidity of around 50% is perfect for eggplants. Too little, and the plant will struggle to stay hydrated.

Humidity that’s too high impedes pollination and can cause fungal disease, especially of the leaves.

USDA Hardiness Zones

Eggplant vines are hardy for USDA Hardiness Zones 10 to 12, but this is somewhat misleading – it’s the range in which this plant will grow naturally as a perennial.

It’ll grow comfortably as far north as USDA Hardiness Zone 4 with the right precautions and a bit of luck.

Organic Material and Fertilizer

Getting your fertilization right is key to lots of delectable mature fruit. Eggplants are heavy feeders and need fertile soil.

Start by amending the soil prior to planting with well-rotted compost or manure. This will set the stage, helping the soil retain water and encouraging beneficial microbes.

As the season progresses, you can side-dress your eggplants with phosphorus and potassium-rich fertilizer – the last two letters in an NPK ratio.

Too much N – nitrogen – will encourage leaves, stems, and runners at the expense of your crop.

Bone meal, kelp meal, and specialist blends designed for tomatoes are good choices. They’ll support the flowering you need for a big harvest.

How to Propagate Eggplants

eggplant seedling sprouting from seeding tray

The most reliable way to propagate eggplants is via seed. You’ll want to start them off around eight weeks before you want to move them to the garden.

To do this, you will need the following:

  • Eggplant seeds
  • Seed raising mix
  • Seed trays or punnets
  • Propagation tray
  • Heating pad (Optional)

Step One: Prepare your Punnets

Fill your seed tray or punnets with the seed-raising mix. Water deeply, ensuring the seed-raising mix is moist. Commercial plastic trays are perfect, but any small pot or container will do.

Step Two: Plant your Seeds

Plant your seeds two to a punnet no more than a quarter of an inch deep by poking a small hole and inserting the seeds.

Step Three: Seal

Place your seedlings in your propagation tray. This is a large, flat tray with a clear lid designed to retain heat and humidity, giving your baby plants their best start in life.

You can get the same effect with any large, clear container.

Place the tray in a warm, well-lit area away from direct light. If using a heating pad, keep the tray at around 75 to 85 degrees Fahrenheit.

Step Four: Water and Wait

Eggplant seeds take around a week or two to sprout. During this time, keep their soil moist without being soggy, and ensure they receive lots of bright, indirect light.

Step Five: Prepare for Transplant

Once the eggplant seeds have sprouted their first mature leaves, remove any weak or straggly plants, and when they reach around five inches tall, cut back on their watering to start hardening them off.

Two weeks before planting, take the young plants outdoors for short periods, leaving them in a shaded position. This is known as hardening off and prepares them for life on the outside.

If you’re in a colder area, consider using a cold frame to protect them during this process.

Step Six: Transplant

Once temperatures are good, prepare your beds by adding compost or manure and watering deeply. Plant your seedlings around a foot apart to ensure good ventilation through the leaves.

Common Problems with Eggplant

red ants on eggplant fruit

Eggplant Pests

Despite having poisonous leaves, insects love to take a nibble at eggplant vines.

Flea beetles, cutworms, eggplant lace bugs, spider mites, and Colorado potato beetles are just a few of the noxious visitors who love to dine on your poor vine.

In most cases, insecticidal soap can help control infestations, or you can dust with diatomaceous earth. You can also use row covers to provide an effective physical barrier against insects.

To prevent overheating, it’s best to pop them off when temperatures exceed 85 degrees Fahrenheit.

Eggplant Disease

The most common eggplant problem in the home garden is powdery mildew.

The best way to avoid this is by planting at the recommended density and pruning low-sprouting vines down at the base of the plant, known as ‘suckers.’

You can also opt for disease-resistant varieties.

Fungal diseases, leaf blights, and rusts caused by bacteria and fungi native to most garden soils cause patches of discoloration.

They’re best prevented by watering the soil, not the leaf, and avoiding splashing dirt onto the foliage by using drip irrigation. A commercial fungicide will often limit the spread and allow recovery.

Verticillium Wilt is the hardest of all to treat.

It attacks the plant’s vascular tissue, causing leaves to yellow, stems to blacken, and the whole plant to fail. It’s a viral issue, and the best prevention is to practice crop rotation.

The disease will die off without a host plant, so next season, swap out this member of the nightshade family with other non-nightshade crops, like brassicas or legumes.

How to Harvest Eggplants

farmer harvesting eggplant fruits in greenhouse

Ripe eggplants can be identified by the color of the fruit. Look for deep purple-black hues for black eggplants and purple or yellow tinges for white varieties. 

However, color can be deceptive, so checking the texture is important. Edible eggplants should be firm but not hard and have white flesh with a slight green tint. 

If you’re still uncertain, pick one to sacrifice, cut one crosswise with a sharp knife, and examine the seeds. They should be clearly visible if the eggplant is ready to pick.

If no seeds are in sight, the fruit isn’t ripe yet, and you may want to wait another week before checking again.

Can I grow Eggplants Indoors?

eggplant seedlings growing in indoors in a container

With enough dedication and the right equipment, you can grow eggplants – and, indeed, any plant! – indoors.

Eggplant’s biggest challenge when grown indoors is light. They need as much direct sun as possible, and many indoor growers achieve this with a grow light setup.

This will ensure the plant receives the 8 to 10 hours of bright, broad-spectrum light needed for fruiting.

Eggplants in large containers also need more frequent feeding.

You’ll need to provide a low-nitrogen fertilizer, preferably water-soluble, at least once a week to ensure they stay fed. Compost tea is a good organic option.

They’re hungry plants, after all. You will also benefit from adding a trellis to support their growth.

A tomato cage will help contain the vigor of these otherwise bushy plants.

Different Varieties of Eggplant to Grow at Home

white eggplant growing in field

Globe/American Eggplant

Globe/American eggplants are a popular variety of eggplant with fruit that’s round, slightly flattened, and dark purple. Compared to traditional Japanese or Chinese varieties, these eggplants are bigger and meatier in texture.

When it comes to growing Globe/American eggplants, they’re best suited for warmer climates with plenty of sun exposure.

Indian Eggplant

Indian eggplant, also known as baby or brinjal eggplants, is a variety of eggplant that originates from India. Unlike other types of eggplant, Indian eggplants are small and round in size and have a milder flavor.

Unsurprisingly, they’re popular in India and are commonly used to make dishes such as bhaji, curry, and chutney. 

Italian Eggplant

The Italian eggplant is a large, dark fruit with a teardrop shape with a much sweeter flavor than the globe eggplant. Although not originating from Italy, these eggplants are famous for their creamy texture.

Rosa Bianca Eggplant

One of the prettiest eggplant varieties, this beautiful eggplant has a bulbous shape with attractive purple and white markings that is slightly less bitter tasting than its purple cousins. 

Once cooked, it’ll lose its vibrancy but gain credit for its lack of seeds, making it a perfect baked fruit for guests.

Thai Eggplant

Grown in Southeast Asia, the Thai eggplant enjoys tropical climates. It’s one of the small varieties, producing golf ball-sized fruit that is fairly bitter.

You can remove the seeds before cooking to take the edge off the bitterness. Mostly found in green, they are also purple and white.

White Eggplant

This fun fruit can brighten up any allotment or garden bed thanks to its pure white color. 

Its flavor is blander than the purple eggplants, which can be a good option if you find conventional eggplants overpowering or bitter.

Fairy Tale Eggplant

Fairy Tale eggplant is an heirloom variety with beautiful purple-striped and white-fleshed fruits. It produces medium-sized fruits with a delightful creamy bite and delicious, delicate flavor.

It’s perfect for stuffing and roasting as it holds its shape well after cooking.

Its small size makes it great for the home gardener because the plant only takes up a little space in the garden. Its fruits have good yields at maturity, making it a worthwhile addition to any edible landscape. 

Chinese Eggplant

Chinese eggplant is generally round, has a mild, slightly sweet flavor, and is believed to be the first commercially cultivated eggplant species in Asia.

When it comes to growing Chinese eggplants, they prefer warm climates and require full sun exposure for optimal growth.

Black Beauty Eggplant

Black Beauty is a type of eggplant known for its deep purple-black color and slight, nutty flavor. It’s popular among gardeners because of its vigorous growth, disease resistance, and compact size.

This makes it perfect for smaller gardens or containers.  As an added bonus, dark skin helps protect against sunburns when exposed to direct sunlight.

Tips for Getting the Most Out Of Your Perrenial Eggplants

eggplant plant with fruits  in garden

  • Select the variety well suited to your area or environmental conditions.
  • Plant late when the frost has completely gone as it is a warm weather crop.
  • Start your eggplant germination process when the temperature is continuously above 70 Fahrenheit.
  • Regularly mist rather than watering heavily to the eggplant seedlings.
  • Make sure your eggplant is not rootbound.
  • Protect the plants from extreme sunlight during peak summer days at midday via shades.
  • Cover over in winter to ensure warm soil.
  • Consider growing them in containers to move them indoors for winter. 
  • Use trellises or stakes when the plant matures and begins fruiting.

Frequently Asked Questions

eggplants growing in hydroponic system in indoor conditions

How Long Do Eggplants Live?

An eggplant vine that’s well-supported and grown in a warm environment will live to be around three years old.

Does Eggplant Need to Be Replanted Every Year?

In warm conditions, eggplants don’t need to be replanted each year. But if your winters bring frost, the chill will kill the vine, and you’ll need to replant come spring.

Will Eggplants Keep Producing?

Well-fed eggplants that receive enough water and light will produce fruit each season for their full three-year lifespan. Plants grown in controlled conditions, like inside a greenhouse or using hydroponics, often produce two or three crops yearly.

Do Eggplants Self-Fertilize?

Eggplants, like tomatoes, are wind pollinated. So long as you have many flowers, they’ll self-fertilize just fine. High humidity and heavy rainfall can cause the pollen to become too heavy and unable to move from the male flower to the female parts of the flower.

Can You Grow Eggplants Hydroponically?

Eggplants are a great choice to grow hydroponically when provided the nutrient solution and grow lights that meet the growing requirements of these plants.

Moreover, make sure to use a variety well suited for hydroponic systems just like black beauty or Japanese eggplant.

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