What to Plant in May
Portland, ME · Zone 5b
Last frost: May 5
Frost-free days: 153
Frost may still be possible early in the month. Harden off your indoor seedlings and transplant after your last frost date. Direct sow beans, squash, and cucumbers once the soil warms.
May at a Glance
Indoor
Transplant
Direct Sow
Start Indoors 14
Start these seeds indoors under grow lights or on a sunny windowsill.
Parsley
Feb 1 – May 23
4 per sq ft
70–90 days
Artichoke
Feb 15 – May 8
1 per sq ft
85–100 days
Broccoli
Feb 15 – Jun 15
1 per sq ft
60–100 days
Cabbage
Feb 15 – Jun 8
1 per sq ft
70–100 days
Cauliflower
Feb 15 – Jun 15
1 per sq ft
55–100 days
Kale
Feb 22 – Jul 16
1 per sq ft
50–65 days
Strawberry
Feb 22 – May 16
4 per sq ft
60–90 days
Oregano
Mar 1 – May 8
1 per sq ft
60–90 days
Lettuce
Mar 9 – Jun 15
4 per sq ft
45–60 days
Spinach
Mar 9 – May 23
9 per sq ft
35–50 days
Swiss Chard
Mar 9 – Jul 31
4 per sq ft
50–60 days
Squash
Apr 24 – Jun 15
1 per sq ft
45–65 days
Zucchini
Apr 24 – Jun 15
1 per sq ft
45–60 days
Cucumber
May 9–31
2 per sq ft
50–70 days
Growing guide
Transplant 23
Move these seedlings from indoors to your garden beds.
Plant now
Chives
Apr 9 – Jun 30
9 per sq ft
60–90 days
Mint
Apr 9 – Jun 30
4 per sq ft
60–90 days
Parsley
Apr 9 – Jul 31
4 per sq ft
70–90 days
Broccoli
Apr 9 – Aug 8
1 per sq ft
60–100 days
Brussels Sprouts
Apr 9 – Jul 16
1 per sq ft
80–110 days
Cabbage
Apr 9 – Jul 31
1 per sq ft
70–100 days
Cauliflower
Apr 9 – Aug 8
1 per sq ft
55–100 days
Kale
Apr 9 – Aug 31
1 per sq ft
50–65 days
Leek
Apr 9 – Jun 23
4 per sq ft
90–150 days
Lettuce
Apr 9 – Jul 16
4 per sq ft
45–60 days
Onion
Apr 9 – Jun 30
9 per sq ft
100–120 days
Spinach
Apr 9 – Jun 23
9 per sq ft
35–50 days
Strawberry
Apr 9 – Jun 30
4 per sq ft
60–90 days
Swiss Chard
Apr 9 – Aug 31
4 per sq ft
50–60 days
Oregano
Apr 24 – Jun 30
1 per sq ft
60–90 days
Rosemary
Apr 24 – May 16
1 per sq ft
80–120 days
Sage
Apr 24 – Jun 15
1 per sq ft
75–90 days
Thyme
Apr 24 – Jun 23
4 per sq ft
70–90 days
Artichoke
Apr 24 – Jul 16
1 per sq ft
85–100 days
Celery
Apr 24 – Jul 8
4 per sq ft
80–120 days
Later this month
Squash
May 17 – Jul 8
1 per sq ft
45–65 days
Tomato
May 17–31
1 per sq ft
65–80 days
Growing guide
Zucchini
May 17 – Jul 8
1 per sq ft
45–60 days
Direct Sow 7
Plant these seeds directly into the soil outdoors.
Cilantro
Apr 1 – Jul 16
9 per sq ft
30–45 days
Beet
Apr 1 – Sep 8
9 per sq ft
50–70 days
Peas
Apr 1 – Aug 31
8 per sq ft
55–70 days
Radish
Apr 1 – Jul 16
16 per sq ft
22–30 days
Turnip
Apr 1 – Sep 23
9 per sq ft
30–60 days
Carrot
Apr 9 – Aug 8
16 per sq ft
70–80 days
Potato
Apr 16 – Jul 8
1 per sq ft
70–150 days
May Gardening Tips
- Start Cucumber, Squash, Zucchini indoors now to give them a head start before transplanting outside.
- Tomato, Squash, Zucchini 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.
- Mulch around transplants with 2–3 inches of straw or shredded leaves to retain moisture and suppress weeds.
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