What to Plant in March
USDA Zone 4b
Last frost: May 1 – May 15
Frost-free days: 120–150
Spring is still weeks away outdoors, but indoor seed starting is in full swing. Start tomatoes, peppers, and herbs under lights. Prepare beds for cool-season crops that go out next month.
March at a Glance
Indoor
Transplant
Direct Sow
1
5
10
15
20
25
Snapdragons
Alyssum
Dahlias
Parsley
Chives
Thyme
Oregano
Sage
Mint
Tomatoes
Peppers
Eggplant
Broccoli
Cauliflower
Cabbage
Brussels Sprouts
Kale
Lettuce
Kohlrabi
Start Indoors 19
Start these seeds indoors under grow lights or on a sunny windowsill.
Snapdragons
Mar 1–8
Parsley
Mar 1–15
4 per sq ft
70–90 days
Chives
Mar 1–8
9 per sq ft
60–90 days
Thyme
Mar 1–8
4 per sq ft
70–90 days
Oregano
Mar 1–8
1 per sq ft
60–90 days
Sage
Mar 1–8
1 per sq ft
75–90 days
Peppers
Mar 1–15
1 per sq ft
60–100 days
Eggplant
Mar 1–15
1 per sq ft
70–90 days
Broccoli
Mar 1–15
1 per sq ft
60–100 days
Cauliflower
Mar 1–15
1 per sq ft
55–100 days
Cabbage
Mar 1–15
1 per sq ft
70–100 days
Brussels Sprouts
Mar 1–15
1 per sq ft
80–110 days
Alyssum
Mar 15–22
Dahlias
Mar 15–22
Mint
Mar 15–22
4 per sq ft
60–90 days
Tomatoes
Mar 15 – Apr 1
1 per sq ft
65–80 days
Kale
Mar 15 – Apr 1
1 per sq ft
50–65 days
Lettuce
Mar 15 – Apr 1
4 per sq ft
45–60 days
Kohlrabi
Mar 15–22
March Gardening Tips
- Start Lettuce, Broccoli, Cabbage indoors now to give them a head start before transplanting outside.
- Add compost to beds now so nutrients are available when planting time arrives.
Ready to plan your garden?
Add these crops to your garden plan and get personalized planting reminders for Zone 4b.
Start Planning Free