What to Plant in April
USDA Zone 4a
Last frost: May 1 – May 15
Frost-free days: 120–150
The season is opening up. Direct sow cold-hardy crops like peas, spinach, and radishes as soon as the ground thaws. Continue starting warm-season seedlings indoors.
April at a Glance
Indoor
Transplant
Direct Sow
1
5
10
15
20
25
Marigolds
Zinnias
Nasturtiums
Sweet Peas
Basil
Cilantro
Tomatoes
Kale
Lettuce
Spinach
Peas
Cucumbers
Summer Squash
Winter Squash
Pumpkins
Carrots
Beets
Radishes
Turnips
Onions (sets)
Onions (seed)
Potatoes
Swiss Chard
Kohlrabi
Start Indoors 12
Start these seeds indoors under grow lights or on a sunny windowsill.
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
Marigolds
Apr 1–15
Basil
Apr 1–15
4 per sq ft
25–35 days
Swiss Chard
Apr 1–8
4 per sq ft
50–60 days
Zinnias
Apr 15–22
Nasturtiums
Apr 15–22
Cucumbers
Apr 15 – May 1
2 per sq ft
50–70 days
Summer Squash
Apr 15 – May 1
Winter Squash
Apr 15 – May 1
Pumpkins
Apr 15 – May 1
¼ per sq ft
85–120 days
Transplant 3
Move these seedlings from indoors to your garden beds.
Lettuce
Apr 15 – May 1
4 per sq ft
45–60 days
Onions (seed)
Apr 15 – May 1
9 per sq ft
100–120 days
Kohlrabi
Apr 15 – May 1
Direct Sow 12
Plant these seeds directly into the soil outdoors.
Sweet Peas
Apr 1–15
Spinach
Apr 1 – May 1
9 per sq ft
35–50 days
Peas
Apr 1 – May 1
8 per sq ft
55–70 days
Cilantro
Apr 15 – May 15
9 per sq ft
30–45 days
Lettuce
Apr 15 – Jun 1
4 per sq ft
45–60 days
Carrots
Apr 15 – May 15
16 per sq ft
70–80 days
Beets
Apr 15 – May 15
9 per sq ft
50–70 days
Radishes
Apr 15 – Aug 1
16 per sq ft
22–30 days
Turnips
Apr 15 – May 1
9 per sq ft
30–60 days
Onions (sets)
Apr 15 – May 1
9 per sq ft
100–120 days
Potatoes
Apr 15 – May 1
1 per sq ft
70–150 days
Kohlrabi
Apr 15 – May 1
April Gardening Tips
- Start Lettuce, Kale, Tomatoes indoors now to give them a head start before transplanting outside.
- Lettuce, Onions (seed), Kohlrabi can be transplanted outside this month. Harden off seedlings over 5–7 days before planting out.
- Direct sow Lettuce, Peas, Spinach straight into the garden — no transplanting needed.
- Soil temperature matters more than air temperature for germination. Use a soil thermometer before direct sowing.
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