What to do now
Mildest step first.
- Check the mix temperature with a soil thermometer; aim for 80–85°F.
- If it's below about 75°F, set the tray on a seedling heat mat or somewhere steadily warm.
- Keep the mix moist but not soggy, and give sweet peppers 3 weeks and hot peppers up to 5 before re-sowing.
- If nothing comes up in a warm tray, test the seed: packets over 2 years old often germinate poorly.
Not sure this is it? Check other pepper problems
Is the mix warm enough?
Peppers are slow and fussy about heat. Data compiled by Oregon State University Extension shows pepper seed sprouts best around 85°F and has a minimum of about 60°F. The difference in speed is large: seedlings took about 8 days to emerge at 77–86°F, 12 days at 68°F, and 25 days at 59°F, with little or no germination at 50°F. A seed tray on a cool windowsill or in a basement often sits in the low 60s even when the room feels comfortable, which can make peppers look like they've failed when they're only slow. NMSU's Chile Pepper Institute recommends 80 to 85°F and says chile seeds can take 2 to 4 weeks depending on soil temperature.
How to warm it
A under the tray is the most reliable fix. Use a soil thermometer pushed into the mix rather than guessing from the air. Once seedlings appear, take the tray off the mat and move it under lights, so the warmth doesn't make them stretch. The top of a refrigerator or a spot near, not on, a heat source can also work if it stays warm day and night.
Hot peppers are slower
Hot peppers need extra patience. NMSU notes that some chinense varieties, such as habanero, can take up to 5 weeks, and its tips for Bhut Jolokia (ghost pepper) call for 80–90°F soil and say germination can take more than a month. If you're growing super-hots, start them earlier than sweet peppers, keep them warm, and don't dump the tray too soon.
Too wet or too deep
Too much water is the next most common cause. Seeds kept in soggy mix can rot before they sprout, and seedlings that do emerge can collapse from damping-off. NMSU advises against overwatering while seeds are germinating, and University of Maryland Extension suggests letting the top of the mix dry slightly between waterings. Depth matters too: sow pepper seed about 1/4 inch deep. Seed buried much deeper may not come up at all.
Is it the seed?
If a warm, evenly moist tray still gives you nothing after 3 to 4 weeks, suspect the seed. Pepper seed usually stays good about 2 years when stored cool and dry; older packets, or ones kept in a warm shed, often germinate poorly. Test a few seeds in a damp paper towel in a warm spot before sowing a whole tray. Most guides suggest starting peppers indoors about 8 to 10 weeks before your , so a re-sow within a couple of weeks of that window usually still gives you plants in time.
Growing it again? When to plant pepper for your ZIP code
Growing it again? When to plant korean chili pepper for your ZIP code
- Why aren't my seeds germinating?Cold soil is the most common culprit — most vegetable seeds stall below 60°F, and old or improperly stored seed may not be viable at all.
- Are old seeds still good?Often, yes. Most vegetable seed stays good for 2 to 5 years if it's kept cool and dry, but onion, parsnip and parsley fade after about a year. The way to know for sure is a germination test: 10 seeds in a damp paper towel for 7 to 10 days.
- Why are my seedlings falling over?Seedlings collapsing at the soil line is usually damping off, a disease caused by soilborne fungi and fungus-like water molds that attack stems in wet, poorly ventilated conditions.
- When should I start seeds indoors?Count backward from your last frost date using the seed packet's weeks-to-transplant number — tomatoes usually go in 6–8 weeks before last frost, and peppers a little earlier, about 8–10 weeks.