When to Start Seeds by Zone (4–10)

(All indoor dates are based on weeks before your average last spring frost.)

If you don’t know your last frost date, you can find it by searching:

“Last frost date + your zip code.”

Zone 4

Average Last Frost: Late May to early June

Start Indoors

• Onions: 10–12 weeks before last frost
• Brassicas (broccoli, cabbage, kale): 6–8 weeks before
• Tomatoes: 6–8 weeks before
• Peppers & eggplant: 8–10 weeks before

Direct Sow

• Peas: 4–6 weeks before last frost
• Spinach & lettuce: 4 weeks before
• Carrots & beets: 2–4 weeks before
• Beans & corn: After last frost
• Cucumbers & squash: 1–2 weeks after last frost

Zone 4 gardeners need patience — but once the season hits, it moves quickly.

Zone 5

Average Last Frost: Early to mid May

Start Indoors

• Onions: 10–12 weeks before
• Brassicas: 6–8 weeks before
• Tomatoes: 6–8 weeks before
• Peppers: 8–10 weeks before

Direct Sow

• Peas: 4 weeks before
• Greens: 3–4 weeks before
• Root crops: 2–3 weeks before
• Beans: After frost
• Squash & cucumbers: 1 week after frost

Zone 5 is a beautiful balance of cool crops and warm crops — timing is everything.

Zone 6

Average Last Frost: Mid to late April

Start Indoors

• Onions: 10–12 weeks before
• Brassicas: 6–8 weeks before
• Tomatoes: 6 weeks before
• Peppers: 8 weeks before

Direct Sow

• Peas & spinach: 4 weeks before
• Carrots & beets: 2–3 weeks before
• Lettuce: 2–4 weeks before
• Beans: After frost
• Cucumbers: 1 week after frost

This is where many gardeners accidentally start tomatoes too early. Bigger is not better — leggy plants struggle later.

Zone 7

Average Last Frost: Late March to early April

(This is my sweet spot here in Arkansas.)

Start Indoors

• Onions: January
• Brassicas: Late January–February
• Tomatoes: Mid February
• Peppers: Early to mid February

Direct Sow

• Peas: Late February
• Spinach & greens: Late February–March
• Carrots & beets: March
• Beans: Mid April
• Cucumbers & squash: Late April

Zone 7 moves fast. It can feel like you blink and you’ve missed it. But the key is watching soil temperature — not just the calendar.

Zone 8

Average Last Frost: Early to mid March

Start Indoors

• Onions: December–January
• Brassicas: January
• Tomatoes: Late January–February
• Peppers: January

Direct Sow

• Peas: January–February
• Greens: February
• Root crops: February
• Beans: Late March
• Cucumbers & squash: Early April

Zone 8 gardeners often feel “behind” — but in reality, your season just starts earlier than everyone else’s.

Zone 9

Average Last Frost: February

Start Indoors

• Tomatoes: December–January
• Peppers: December
• Brassicas: Fall start for spring harvest

Direct Sow

• Peas: January
• Greens: Winter
• Beans: March
• Warm crops: After frost risk passes

Zone 9 is unique — fall planting often matters more than spring.

Zone 10

Minimal Frost Risk

Zone 10 gardeners operate differently.

• Tomatoes: Fall planting preferred
• Greens: Winter growing
• Beans & warm crops: Early spring

In these zones, extreme heat becomes the limiting factor — not frost.

Common Seed Starting Mistakes (No Matter Your Zone)

• Starting too early
• Not providing enough light
• Overwatering
• Skipping hardening off
• Ignoring soil temperature

A Quick Word on Frost Dates

If your frost date shifts (and they do), in fact, mine recently went from 7b to 8a, don’t freak out.

Every year is a little different. The goal is just to find a rhmyth that works for you.

Want This Broken Down Into a Printable Guide?

If this helped, I created a Seed Starting by Zone Starter Guide you can download and print.

Inside you’ll get:

• A simple zone-based chart
• Indoor + direct sow timelines
• Planning pages
• Quick reference crop lists

And if you’re ready to map your entire growing year — from January through December — my full Year-Round Seed Starting Guide goes deeper, with monthly breakdowns, planting grids, and physical copies available for your garden binder.

Because once you understand your timing, everything changes.

Talk Soon,

Jill