What to plant in May in Maine
In Maine (ME), the average last frost (May 14) falls in May itself. The state averages 134 frost-free days a year (last frost May 14, first frost September 25; USDA zones 3b, 4a, 4b, 5a, 5b, 6a).
89 crops have a sowing or planting window this month, including cabbage, collard greens, horseradish, kale, kohlrabi, onion - and 48 of those windows close during May.
Dates here come from Maine frost dates (last frost May 14, first frost Sep 25). For one crop in detail, see when to plant cabbage, kale or onion in Maine.
Maine: planting activity through the year
Last chance in May
Cabbage (transplant outdoors, by May 3) · Collard Greens (transplant outdoors, by May 3) · Horseradish (plant crowns / divisions, by May 3) · Kale (transplant outdoors, by May 3) · Kohlrabi (transplant outdoors, by May 3) · Onion (transplant outdoors, by May 3) · Rhubarb (plant crowns / divisions, by May 3) · Shallot (transplant outdoors, by May 3) · Carrot (direct sow (spring), by May 7) · Chervil (direct sow (spring), by May 7) · Endive & Escarole (direct sow (spring), by May 7) · Kohlrabi (direct sow (spring), by May 7) · Lettuce (direct sow (spring), by May 7) · Mustard Greens (direct sow (spring), by May 7) · Rapini (Broccoli Raab) (direct sow (spring), by May 7) · Turnip (direct sow (spring), by May 7) · Watercress (direct sow (spring), by May 7) · Asparagus (plant crowns / divisions, by May 10) · Bok Choy / Pak Choi (transplant outdoors, by May 10) · Broccoli (transplant outdoors, by May 10) · Brussels Sprouts (transplant outdoors, by May 10) · Cauliflower (transplant outdoors, by May 10) · Chives (plant crowns / divisions, by May 10) · Endive & Escarole (transplant outdoors, by May 10) · Leek (transplant outdoors, by May 10) · Lettuce (transplant outdoors, by May 10) · Napa Cabbage (transplant outdoors, by May 10) · Parsley (transplant outdoors, by May 10) · Radicchio (transplant outdoors, by May 10) · Sorrel (plant crowns / divisions, by May 10) · Swiss Chard (transplant outdoors, by May 10) · Watercress (transplant outdoors, by May 10) · Bok Choy / Pak Choi (direct sow (spring), by May 14) · Borage (direct sow (spring), by May 14) · Cilantro / Coriander (direct sow (spring), by May 14) · Collard Greens (direct sow (spring), by May 14) · Kale (direct sow (spring), by May 14) · Leek (direct sow (spring), by May 14) · Napa Cabbage (direct sow (spring), by May 14) · Parsley (direct sow (spring), by May 14) · Potato (direct sow (spring), by May 14) · Radicchio (direct sow (spring), by May 14) · Salsify (direct sow (spring), by May 14) · Fennel (Bulb) (transplant outdoors, by May 17) · Globe Artichoke (plant crowns / divisions, by May 17) · Lemon Balm (transplant outdoors, by May 17) · Mint (transplant outdoors, by May 17) · Tarragon (transplant outdoors, by May 17)
Sow or plant outdoors in May (112)
Direct sowing and transplanting windows that fall in May, most urgent first. Windows are one-to-two-week bands around the ideal date.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Cabbage | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Collard Greens | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Horseradish | Plant crowns / divisions | Apr 16 – May 3 | Last chance - ends May 3 |
| Kale | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Kohlrabi | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Onion | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Rhubarb | Plant crowns / divisions | Apr 16 – May 3 | Last chance - ends May 3 |
| Shallot | Transplant outdoors | Apr 16 – May 3 | Last chance - ends May 3 |
| Carrot | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Chervil | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Endive & Escarole | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Kohlrabi | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Lettuce | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Mustard Greens | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Rapini (Broccoli Raab) | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Turnip | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Watercress | Direct sow (spring) | Apr 18 – May 7 | Last chance - ends May 7 |
| Asparagus | Plant crowns / divisions | Apr 23 – May 10 | Last chance - ends May 10 |
| Bok Choy / Pak Choi | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Broccoli | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Brussels Sprouts | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Cauliflower | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Chives | Plant crowns / divisions | Apr 23 – May 10 | Last chance - ends May 10 |
| Endive & Escarole | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Leek | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Lettuce | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Napa Cabbage | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Parsley | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Radicchio | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Sorrel | Plant crowns / divisions | Apr 23 – May 10 | Last chance - ends May 10 |
| Swiss Chard | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Watercress | Transplant outdoors | Apr 23 – May 10 | Last chance - ends May 10 |
| Bok Choy / Pak Choi | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Borage | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Cilantro / Coriander | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Collard Greens | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Kale | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Leek | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Napa Cabbage | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Parsley | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Potato | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Radicchio | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Salsify | Direct sow (spring) | Apr 25 – May 14 | Last chance - ends May 14 |
| Fennel (Bulb) | Transplant outdoors | Apr 30 – May 17 | Last chance - ends May 17 |
| Globe Artichoke | Plant crowns / divisions | Apr 30 – May 17 | Last chance - ends May 17 |
| Lemon Balm | Transplant outdoors | Apr 30 – May 17 | Last chance - ends May 17 |
| Mint | Transplant outdoors | Apr 30 – May 17 | Last chance - ends May 17 |
| Tarragon | Transplant outdoors | Apr 30 – May 17 | Last chance - ends May 17 |
| Fennel (Bulb) | Direct sow (spring) | May 2 – May 21 | May 2 – May 21 |
| Lemon Balm | Direct sow (spring) | May 2 – May 21 | May 2 – May 21 |
| Parsnip | Direct sow (spring) | May 2 – May 21 | May 2 – May 21 |
| Swiss Chard | Direct sow (spring) | May 2 – May 21 | May 2 – May 21 |
| Celeriac | Transplant outdoors | May 7 – May 24 | May 7 – May 24 |
| Celery | Transplant outdoors | May 7 – May 24 | May 7 – May 24 |
| Oregano | Transplant outdoors | May 7 – May 24 | May 7 – May 24 |
| Sage | Transplant outdoors | May 7 – May 24 | May 7 – May 24 |
| Thyme | Transplant outdoors | May 7 – May 24 | May 7 – May 24 |
| Dill | Direct sow (spring) | May 9 – May 28 | May 9 – May 28 |
| Sunflower | Direct sow (spring) | May 9 – May 28 | May 9 – May 28 |
| Ground Cherry | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| New Zealand Spinach | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Peanut | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Pumpkin | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Rosemary | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Shiso (Perilla) | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Summer Savory | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Sunflower | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Sweet Marjoram | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Tomatillo | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Tomato | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Winter Squash | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Zucchini / Summer Squash | Transplant outdoors | May 14 – May 31 | May 14 – May 31 |
| Amaranth (Leaf) | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Bush Bean | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Edamame (Soybean) | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| New Zealand Spinach | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Pole Bean | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Pumpkin | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Shiso (Perilla) | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Summer Savory | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Sweet Corn | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Sweet Marjoram | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Winter Squash | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Zucchini / Summer Squash | Direct sow (spring) | May 16 – Jun 4 | Opens May 16 |
| Basil | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Bell Pepper | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Bitter Melon | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Cantaloupe / Muskmelon | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Chili Pepper | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Cucamelon | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Cucumber | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Luffa (Loofah Gourd) | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Malabar Spinach | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Okra | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Watermelon | Transplant outdoors | May 21 – Jun 7 | Opens May 21 |
| Basil | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Bitter Melon | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Cantaloupe / Muskmelon | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Chayote | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Cucamelon | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Cucumber | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Lima Bean | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Luffa (Loofah Gourd) | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Malabar Spinach | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Okra | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Peanut | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Southern Pea (Cowpea) | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Watermelon | Direct sow (spring) | May 23 – Jun 11 | Opens May 23 |
| Eggplant | Transplant outdoors | May 28 – Jun 14 | Opens May 28 |
| Ginger | Transplant outdoors | May 28 – Jun 14 | Opens May 28 |
| Sweet Potato | Transplant outdoors | May 28 – Jun 14 | Opens May 28 |
| Turmeric | Transplant outdoors | May 28 – Jun 14 | Opens May 28 |
For fall and winter harvests (1)
Sowings counted back from Maine's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Brussels Sprouts | Start transplants for fall | May 26 – Jun 12 | Opens May 26 |
Keep sowing (succession)
Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.
- Pea: sow again on May 3 and May 15 and May 27
- Spinach: sow again on May 3 and May 15 and May 27
- Beet: sow again on May 4 and May 22
- Radish: sow again on May 6 and May 16 and May 26
- Arugula: sow again on May 10 and May 22
- Green Onion / Scallion: sow again on May 7 and May 28
- Mache (Corn Salad): sow again on May 7 and May 21
- Tatsoi: sow again on May 10 and May 22
- Mizuna: sow again on May 10 and May 22
Harvesting in May
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Maine
Every crop has its own full-year dates for Maine: indoor start, transplant or direct sowing, and harvest.
Main planting month: May garden jobs in Maine
- With the average last frost on May 14, 80 crops can go in outdoors this month, including cabbage, collard greens, horseradish, kale.
- Transplant on a cloudy afternoon and water in well - see transplanting seedlings without shock.
- Once the soil has warmed, lay mulch around established plants to hold moisture and smother weeds.
- Sow quick crops little and often - lettuce, radish and beans every two to three weeks give a steady harvest instead of a glut (succession planting).
USDA zone chart for Maine
Maine spans USDA zones 3b, 4a, 4b, 5a, 5b, 6a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Maine in May?
89 crops have a window in May: cabbage, collard greens, horseradish, kale, kohlrabi, onion, rhubarb, shallot, carrot, chervil and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Maine in May?
No - transplant outdoors runs May 14 – May 31 in Maine, so do it before May 31.
Is it too late to plant lettuce in Maine in May?
No - direct sow (spring) runs Apr 18 – May 7 in Maine, so do it before May 7.
When is the first frost in Maine?
The statewide average first fall frost is around September 25 and the last spring frost around May 14. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Maine in May?
From plantings made on time: radish, spinach, arugula, tatsoi, mizuna, mustard greens, mache (corn salad), lettuce.
What to plant in May in other states
Dates are computed from Maine’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.