Is it too early to start seeds when there's still snow on the ground? For most crops, yes. But a handful of slow growers need a big head start indoors, or they won't have time to produce before fall. In this guide, you'll learn which crops to start first, when to sow them and how to grow strong seedlings.
Why do some crops need an early start?
Some plants germinate slowly, grow slowly as seedlings or need a long season to mature. If you sow them outdoors after your last frost, the first fall frost can arrive before they've produced a good harvest. Starting them indoors 10 to 12 weeks early gives them the time they need.
Here in Minnesota, zone 5a, with a last frost in mid-to-late May, that means sowing these in late February and March.
1. Hot peppers
Peppers are slow to sprout and slow to grow, and hot peppers are often the slowest of all.
- When to sow: About 8 to 12 weeks before your last frost. Give the slowest types, like habaneros, the longer end of that range.
- Germination: Keep soil warm, about 75 to 85°F. A seedling heat mat helps a lot. Seeds may take 1 to 3 weeks to sprout.
- Top picks: Serrano (about 75 to 85 days from transplant), a productive, fiery salsa pepper, and Habanero (about 90 to 100 days from transplant), very hot and fruity.
2. Onions from seed
Onion sets are convenient, but growing from seed gives you more variety choices and onions that often store better.
- Why timing matters: Onions form bulbs in response to day length. Long-day onions, which suit northern gardens, start bulbing as days get long in early summer. The bigger the plant is by then, the bigger the bulb.
- When to sow: About 10 to 12 weeks before your last frost.
- Tip: Give seedlings a “haircut” to about 3 to 4 inches tall whenever they flop over. It keeps them sturdy.
- Transplant: Plant out about 2 to 4 weeks before your last frost. Onion seedlings handle light frost.
- Top pick: Yellow Sweet Spanish (about 110 to 120 days): a large, mild, long-day onion that's a great fit for northern gardens.
3. Lavender
Lavender is slow and sometimes stubborn to germinate, but it's well worth the wait.
- When to sow: About 10 to 12 weeks before your last frost.
- Cold treatment: Germination often improves if you chill the seeds first. Place them in a damp paper towel in a bag in the fridge for about 3 to 4 weeks before sowing.
- How to sow: Press seeds onto the surface of the mix and barely cover them. They need some light. Expect sprouts in about 2 to 4 weeks.
- Top pick: Vera Lavender: a classic, fragrant English lavender that's hardy to about zone 5.
Tips for growing strong early seedlings
- Light: Windowsills rarely give enough light in late winter. Hang a shop light or grow light 2 to 4 inches above seedlings for 14 to 16 hours a day.
- Water: Keep the mix moist, not soggy. Water from below when the top feels dry.
- Air: A small fan on low strengthens stems and helps prevent damping off.
- Feed: Once true leaves appear, feed with a half-strength liquid fertilizer every week or two.
- Harden off: Gradually introduce seedlings to outdoor conditions over a week before planting out.
Start your slow pokes on time
Mark your calendar for 10 to 12 weeks before your last frost and get these seeds started. Your future self will thank you in August. All our seeds are non-GMO and USA grown, and I pack every packet myself here in Minnesota. For a bundle of varieties in one go, take a look at our Colorful Garden Kit.
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