Harvest guide
When to Plant Eggplant (Soil Temp + Frost Timing)
Set eggplant transplants out 1 to 3 weeks after your last spring frost, once the soil hits 60 to 70 F and nights stay above 50 F. Start seeds indoors 6 to 10 weeks before that frost date.
Days to maturity
65–80days
Ready when
Glossy skin that springs back when pressed
The short answer
Set eggplant transplants out 1 to 3 weeks after your last spring frost, once the soil reads 60 to 70 F and nights stay above 50 F. Eggplant wants more heat than tomatoes, so wait for warm ground, not just a frost-free date. Start seeds indoors 6 to 10 weeks before that frost.
Eggplant is a heat lover. It came from the tropics, and it shows. Plant it into cold soil and it just sits there, yellowing, while pests move in. Plant it into warm soil a couple of weeks after your frost date and it takes off. This guide covers when to plant by zone, the soil-temperature cue that matters more than the calendar, and when to start seeds.
When to plant eggplant by zone
The target is the same everywhere: warm soil and warm nights. Oregon State Extension sets the bar at soil of at least 60 F and night lows around 65 to 70 F for good growth. UMN Extension is blunter: transplant only after night temperatures hold above 50 F, with soil near 70 F best.
Colder zones reach that point later, so they plant later. The windows below are starting points. Your own last-frost date and a soil thermometer beat any calendar.
| Region / zone | Typical planting window | Method |
|---|---|---|
| Cold (zones 3–5) | Late May – June | Transplants only |
| Temperate (zones 6–7) | Mid-May – early June | Transplants only |
| Mild (zones 8–9) | April – May | Transplants (second fall crop possible) |
| Hot (zone 10) | Spring + late summer | Two crops, transplants |
Notice the method column. Across the country, eggplant goes in as a transplant, not direct-seeded. The season is too long from seed for most of the US.
Wait for warm soil, not just the last frost
Here is the part most planting charts skip. Eggplant needs more heat than tomatoes or peppers, so the frost-free date is the earliest you might plant, not the day you should.
Illinois Extension and UMN both treat eggplant as a warm-season crop that suffers in cool conditions. Several extensions recommend setting it out 1 to 3 weeks after the last frost, once the soil and nights have actually warmed.
Check two things before you plant:
- Soil temperature. Push a soil thermometer 2 to 3 inches down in the morning. You want a steady 60 F, ideally closer to 70 F.
- Night lows. They should hold above 50 F, with no cold snap in the 10-day forecast.
Pro tip
Warm the soil ahead of planting. Lay black plastic or dark mulch over the bed for a week or two before transplanting, especially in cooler zones. It can lift the top few inches of soil several degrees and gets eggplant off to a faster start. UF/IFAS notes eggplant is a warm-season crop that benefits from warm soil, so this small step pays back in earlier fruit.
When to start eggplant seeds indoors
Eggplant is slow from seed, so start early. Sow seeds indoors 6 to 10 weeks before your last spring frost. Oregon State suggests roughly 8 to 10 weeks of indoor growth, while the USDA plant guide lists 6 to 8 weeks at warm temperatures.
Count backward from your frost date to set the sow date. A gardener with a May 15 frost date starts seeds around early to mid-March.
Then harden the seedlings off for a week before they go out, easing them into sun and wind. Transplants want to be 6 to 8 weeks old and stocky, not leggy, by planting day.
Spring vs fall planting
For most of the country, spring is the only planting. You set transplants out after the soil warms, and the plants fruit through summer into early fall.
The exception is the hot South. In zones 8 to 10, the summer can be long enough for two crops. Gardeners there often plant once in spring, then set out a second round of transplants in mid to late summer for a fall harvest, once the fiercest heat starts to ease. There has to be enough warm time left to mature fruit before the first fall frost.
In zone 7 and colder, skip the fall crop. The season runs out before a late planting can produce.
Common mistakes
The big one is planting too early. Eggplant sitting in cold, wet soil does not just pause. It stunts, yellows, and draws flea beetles, and it rarely fully recovers even when the weather turns.
Common mistake
Planting eggplant the same day as tomatoes is the classic error. Tomatoes tolerate soil in the low 60s F. Eggplant wants it warmer and nights above 50 F, so the same calendar date that suits tomatoes can leave eggplant cold and checked. Give eggplant an extra 1 to 3 weeks, or warm the bed with plastic first. The wait costs nothing and the plant grows faster for it.
A second mistake is crowding. Eggplant grows into a wide, branching plant, so give each one room. The companion guide on how far apart to plant eggplant walks the spacing, and once the plants set fruit, when to harvest eggplant covers the glossy-skin test for picking.
Your next step
Plant eggplant when the ground is warm, which is 1 to 3 weeks after your last frost in most zones, with soil at 60 to 70 F and nights above 50 F. Start seeds indoors 6 to 10 weeks before that frost, harden the seedlings off, and warm the bed with dark plastic if your spring runs cool.
Timing eggplant is a lot like timing its bed-mates. The same heat rules drive when to plant peppers, and the slightly earlier window for when to plant tomatoes is the one to check first if you are planning the whole warm-season bed.
Common questions
What is the best month to plant eggplant?
It depends on your frost date, not the calendar. Eggplant goes out 1 to 3 weeks after the last spring frost, so April to May in mild zones (8 to 9), May in temperate zones (6 to 7), and late May into June in cold zones (3 to 5). Soil should read 60 to 70 F first.
How warm does the soil need to be to plant eggplant?
At least 60 F, and 70 F is better. UMN Extension says eggplant needs warm weather and a soil temperature near 70 F to thrive, and that night temperatures should stay above 50 F before you transplant. Cold soil stalls the plants and invites disease, so wait it out.
When should I start eggplant seeds indoors?
Start seeds indoors 6 to 10 weeks before your last spring frost. Oregon State Extension suggests about 8 to 10 weeks of indoor growth, and the USDA plant guide lists 6 to 8 weeks. Eggplant is slow from seed, so the head start matters in short-season zones.
Can you plant eggplant in the fall?
In warm zones, yes. In zones 8 to 10, gardeners often set out a second crop in mid to late summer for fall harvest, once the worst heat eases but with enough warm weeks left before frost. In zones 7 and colder, fall is too short and cool for a second eggplant crop.
Should I plant eggplant at the same time as tomatoes?
Wait a little longer. Eggplant needs more heat than tomatoes, so extension sources recommend setting it out 1 to 3 weeks after the frost date rather than right at it. If you plant both the same day, the eggplant often sulks in soil that suits the tomatoes fine.
Sources
Agronomic claims in this guide are checked against these primary sources.
- Growing eggplant in home gardens — University of Minnesota Extension
- Eggplant | Home Vegetable Gardening — University of Illinois Extension
- Growing eggplant in your garden — Oregon State University Extension
- Eggplant — UF/IFAS Gardening Solutions
Keep reading
When to Harvest Eggplant (Signs It's Ready)
Eggplant is ready about 65 to 80 days after transplanting, picked young while the skin is glossy and firm. Here are the signs, the thumb press test, and how to cut it clean without snapping the woody stem.
Read →When to Plant Peppers (Frost Timing by Zone)
Start pepper seeds indoors 8 to 10 weeks before your last spring frost, then set transplants out 1 to 2 weeks after the frost passes, once soil hits 60 to 65 F and nights stay above 50 to 55 F.
Read →When to Plant Tomatoes (Frost + Soil Temp by Zone)
Set tomato transplants out 1 to 2 weeks after your last spring frost, once soil hits at least 60 F. Start seeds indoors 6 to 8 weeks before that frost date. Cold soil stalls them, so wait for warmth.
Read →When to Plant Zucchini (Frost + Soil Temp Timing)
Plant zucchini after your last spring frost, once the soil hits at least 60 F (ideally 65 to 70 F). Direct-sow seeds 1/2 to 1 inch deep, or set out transplants started 2 to 4 weeks earlier. Warm zones get a second fall crop.
Read →When to Plant Swiss Chard (Spring and Fall Timing)
Plant swiss chard 2 to 4 weeks before your last spring frost, once the soil hits 40°F. Sow again 3 to 4 weeks before the first fall frost. Seeds go half an inch to an inch deep.
Read →When to Plant Sweet Potatoes (Soil Temp + Frost Timing)
Plant sweet potato slips 2 to 4 weeks after your last spring frost, once soil holds above 65°F. Get timing by zone, the soil-temp gate, and the mistake that rots slips in cold ground.
Read →