Last Updated on October 9, 2026
How to Start Eggplant Seeds Indoors
Start eggplant seeds indoors 6 to 7 weeks before your last spring frost and plant them out 2 to 3 weeks after it. Sow them 1/4 inch deep, keep the mix at 75-85°F on a heat mat until they come up, then grow them warm under lights hung 2 to 4 inches above the leaves.
That window is the one the Plan My Garden planner uses for eggplant. To turn it into dates, look up your last frost date by zip code or enter it on my seed starting calendar.
The eggplant seed starting timeline
| Step | When | Basis |
|---|---|---|
| Sow indoors | 6 to 7 weeks before your last frost | Plan My Garden planner |
| Seedlings come up | About 5 to 8 days later at 77-86°F soil | My germination chart |
| Pot up | 2 to 3 weeks after they come up | University of Maryland Extension |
| Harden off | The 1 to 2 weeks before you plant out | UMN Extension + planner |
| Plant out | 2 to 3 weeks after your last frost | Plan My Garden planner |
Eggplant spends longer indoors than peppers or tomatoes: 8 to 10 weeks by the planner’s own sow and plant-out weeks, against 8 to 9 for peppers and 5 to 8 for tomatoes. University of Maryland Extension puts pepper, eggplant and onion transplants at that same 8 to 10 week age, well above tomato’s 5 to 6. University of Missouri Extension lists eggplant among the seedlings with slower early root development, the likely reason it needs the longer head start.
How fast eggplant seeds sprout by soil temperature
These are the days to emerge from my seed germination temperature chart, which uses J.F. Harrington’s UC Davis data.
| Soil temperature | Days for eggplant seedlings to emerge |
|---|---|
| 32°F | Little or no germination |
| 41-59°F | Not tested |
| 68°F | About 13 |
| 77°F | About 8 |
| 86°F | About 5 |
| 95°F and up | Not tested |
My chart puts the eggplant optimum at 75-85°F, with 60°F as the minimum and 95°F as the maximum. South Dakota State University Extension says eggplant seed will not germinate below 60°F. A tray at a 68°F room temperature takes more than twice as long as one at 86°F.
Bottom heat
A seedling heat mat with a thermostat is the easy way to hold that range. University of Minnesota Extension says to keep the flat at 75-85°F until seedlings emerge and to watch the moisture, because heat mats dry the mix out faster. Its seed starting guide adds that the mix in indoor containers can run as much as 5°F cooler than the room air, and that bottom heat can help prevent damping off. Do not plug the mat into your light timer.
Step by step
- Moisten the mix. Wet the seed-starting mix in a bucket before you fill anything. I recommend a mix with compost in it, like Coast of Maine, or my soil block recipe: 1 part peat moss, 1 part Coast of Maine compost blend, 1/2 part vermiculite and a small amount of blood meal.
- Pick cells or blocks. If you are just starting out, I recommend cell packs. Maryland Extension suggests cells of 9 to 16 square inches for tomato, eggplant and pepper, which is 3 by 3 to 4 by 4 inches. Soil blocks are the other option; I recommend 2-inch blocks for starting seedlings.
- Sow 1/4 inch deep. Minnesota Extension says to plant eggplant seeds one-fourth inch deep. I put two seeds in each cell or block.
- Cover and warm. Put a clear dome or plastic wrap over the tray and set it on the heat mat at 75-85°F.
- Uncover and light up. Take the cover off as soon as the seeds sprout, which helps prevent damping off. Hang the lights 2 to 4 inches above the seedlings and run them 12 to 16 hours a day on a timer. Minnesota Extension calls 2 inches ideal and says plants need some dark each night.
- Keep them warm after they sprout. Utah State University Extension grows eggplant seedlings on at 65-75°F.
- Thin to one. Once the true leaves show, snip the weaker seedling at the soil line with scissors. Pulling it can damage the roots of the one you keep.
- Water from below. Pour water into the tray and let the cells drink it up through the holes. For soil blocks I add about an inch of water to the tray daily or every other day.
Maryland Extension says soilless mixes often hold enough fertilizer to support plants for 6 to 8 weeks after germination. Eggplant is indoors longer than that 6 to 8 week window, so potting up into fresh mix partway through makes sense. The general method is in How to Start Seeds Indoors.
Potting up eggplant seedlings
Minnesota, Maryland and Missouri Extension back these steps:
- When: Pot up 2 to 3 weeks after germination, or sooner if roots start to circle the inside of the pot.
- Into what: A container 1 to 2 inches wider than the cell pack. With soil blocks, the 4-inch blocker takes a 2-inch block, the same up-potting step my soil blocks guide shows with tomatoes. More root room makes a bigger seedling.
- How to hold it: By a leaf, never the stem. A seedling can grow a new leaf, but one that loses its main growing point may not survive.
- How deep: Not like a tomato. Eggplant does not root along a buried stem the way tomato does, so set it in the garden at the same depth it grew in the pot.
Slow, leaning or flowering seedlings
| What you see | Likely cause and fix |
|---|---|
| Seeds slow to come up | Mix too cool. At 68°F it takes about 13 days. Raise the mat to 75-85°F. |
| Seedlings barely growing | Too cold, most likely. The University of Maryland’s eggplant page says cold temperatures stop plant and root growth in general, through the whole season. Keep the room at 65-75°F and the tray away from cold drafts. |
| Stems leaning over | Not enough overhead light. Minnesota Extension says eggplant stems lean without bright light directly above them. Lower the lights to 2 inches, and move trays off the windowsill: Maryland Extension says window light is seldom enough for strong seedlings. |
| Flowers indoors | Pinch the flower clusters off until the plants are in the garden (Minnesota Extension). |
Hardening off and planting out
Minnesota Extension starts when plants are about 5 inches tall and 8 to 10 weeks old. Cut back on water, then set them outside with wind protection and a couple of hours of sun. Give them more sun over the next week or two, and bring them in if nights drop below 55°F. My transplanting guide hardens seedlings off over 1 to 2 weeks, out of direct sun at first. A cold frame makes it easier.
Plant out 2 to 3 weeks after your last frost, once the soil has warmed. Eggplant is a tender crop on my frost tolerance chart, and Minnesota Extension says it is much less cold hardy than tomatoes: set out before night lows stay above 50°F, it can suffer from the chill and may never recover. Utah State also waits for 60°F soil, and favors transplants that are stocky, dark green, 5 to 8 inches tall with 6 to 9 leaves; ones with blossoms or fruit establish slowly and yield poorly.
Spacing is on How Many Eggplant Plants per Square Foot?, and harvest timing on the days to maturity chart.
Where to get eggplant seed
Wood Prairie’s organic eggplant seed includes Ping Tung Long, a long Asian type listed at 70 days with fruit 10 to 12 inches long, about 40 seeds to a packet. Their Diamond, a very early type for shorter-season climates, was sold out when this page was written. Code PMG5 takes 5 percent off.
Quick questions
When should I start eggplant seeds indoors?
6 to 7 weeks before your last spring frost, then plant out 2 to 3 weeks after it. That is the Plan My Garden planner’s window.
How long do eggplant seeds take to germinate?
About 5 days at 86°F soil, about 8 days at 77°F and about 13 days at 68°F, from my seed germination temperature chart. South Dakota State University Extension says eggplant seed will not germinate below 60°F.
Do eggplant seeds need a heat mat?
They need warm mix, and a heat mat is the easy way to get it. University of Minnesota Extension keeps the flat at 75-85°F until seedlings emerge. At a 68°F room temperature, expect about 13 days instead of 5 to 8.
Why are my eggplant seedlings growing so slowly?
Check the temperature first. The University of Maryland says cold temperatures stop eggplant’s plant and root growth in general, and University of Missouri Extension lists eggplant among the seedlings with slower root development. Keep them at 65-75°F under lights 2 to 4 inches above the leaves.
When can eggplant seedlings go outside?
2 to 3 weeks after your last frost, after 1 to 2 weeks of hardening off. University of Minnesota Extension waits until night lows stay above 50°F, and Utah State University Extension waits for 60°F soil.
Get your eggplant start week
The planner turns your zip code’s frost dates into start-indoors and transplant dates. Plan My Garden is free to start: enter your zip code and it finds your frost dates, draw your beds, pick eggplant and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule (start indoors, transplant and direct sow dates) from your frost dates.
Related: How to Grow Peppers from Seed · How Many Peppers per Square Foot? · Seed Starting Step by Step · Seed Starting Calendar
