What to Plant in April
Denver, CO · Zone 5b
Last frost: May 5
Frost-free days: 154
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
Chives
Cilantro
Mint
Oregano
Parsley
Sage
Artichoke
Beet
Broccoli
Brussels Sprouts
Cabbage
Carrot
Cauliflower
Celery
Kale
Leek
Lettuce
Onion
Peas
Potato
Radish
Spinach
Strawberry
Swiss Chard
Turnip
Start Indoors 15
Start these seeds indoors under grow lights or on a sunny windowsill.
Celery
Feb 8 – Apr 23
4 per sq ft
80–120 days
Chives
Feb 15 – Apr 15
9 per sq ft
60–90 days
Parsley
Feb 15 – May 8
4 per sq ft
70–90 days
Mint
Feb 22 – Apr 23
4 per sq ft
60–90 days
Artichoke
Feb 22 – Apr 8
1 per sq ft
85–100 days
Broccoli
Mar 1 – May 23
1 per sq ft
60–100 days
Cabbage
Mar 1 – May 23
1 per sq ft
70–100 days
Cauliflower
Mar 1 – May 23
1 per sq ft
55–100 days
Oregano
Mar 9 – Apr 23
1 per sq ft
60–90 days
Sage
Mar 9 – Apr 8
1 per sq ft
75–90 days
Kale
Mar 9 – Jun 23
1 per sq ft
50–65 days
Strawberry
Mar 9 – May 8
4 per sq ft
60–90 days
Lettuce
Mar 24 – May 16
4 per sq ft
45–60 days
Spinach
Mar 24 – May 8
9 per sq ft
35–50 days
Swiss Chard
Mar 24 – Jul 16
4 per sq ft
50–60 days
Transplant 14
Move these seedlings from indoors to your garden beds.
Chives
Apr 24 – Jun 23
9 per sq ft
60–90 days
Mint
Apr 24 – Jun 23
4 per sq ft
60–90 days
Parsley
Apr 24 – Jul 16
4 per sq ft
70–90 days
Broccoli
Apr 24 – Jul 16
1 per sq ft
60–100 days
Brussels Sprouts
Apr 24 – Jul 16
1 per sq ft
80–110 days
Cabbage
Apr 24 – Jul 16
1 per sq ft
70–100 days
Cauliflower
Apr 24 – Jul 16
1 per sq ft
55–100 days
Kale
Apr 24 – Aug 8
1 per sq ft
50–65 days
Leek
Apr 24 – Jun 8
4 per sq ft
90–150 days
Lettuce
Apr 24 – Jun 15
4 per sq ft
45–60 days
Onion
Apr 24 – Jun 8
9 per sq ft
100–120 days
Spinach
Apr 24 – Jun 8
9 per sq ft
35–50 days
Strawberry
Apr 24 – Jun 23
4 per sq ft
60–90 days
Swiss Chard
Apr 24 – Aug 16
4 per sq ft
50–60 days
Direct Sow 7
Plant these seeds directly into the soil outdoors.
Plant now
Cilantro
Mar 17 – Jun 15
9 per sq ft
30–45 days
Turnip
Mar 17 – Sep 23
9 per sq ft
30–60 days
Beet
Mar 24 – Sep 8
9 per sq ft
50–70 days
Carrot
Mar 24 – Jul 31
16 per sq ft
70–80 days
Peas
Mar 24 – Jun 30
8 per sq ft
55–70 days
Radish
Mar 24 – Jun 15
16 per sq ft
22–30 days
Later this month
Potato
Apr 24 – Jul 8
1 per sq ft
70–150 days
April Gardening Tips
- Start Lettuce, Broccoli, Cabbage indoors now to give them a head start before transplanting outside.
- Lettuce, Broccoli, Cabbage can be transplanted outside this month. Harden off seedlings over 5–7 days before planting out.
- Direct sow Carrot, Peas, Potato 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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