What to plant in May in Connecticut
In Connecticut (CT), May comes about 3 weeks after the average last frost (April 25). The state averages 173 frost-free days a year (last frost April 25, first frost October 15; USDA zones 5b, 6a, 6b, 7a).
66 crops have a sowing or planting window this month, including fennel (bulb), lemon balm, parsnip, swiss chard, celeriac, celery - and 36 of those windows close during May.
Dates here come from Connecticut frost dates (last frost Apr 25, first frost Oct 15). For one crop in detail, see when to plant swiss chard, pumpkin or tomato in Connecticut.
Connecticut: planting activity through the year
Last chance in May
Fennel (Bulb) (direct sow (spring), by May 2) · Lemon Balm (direct sow (spring), by May 2) · Parsnip (direct sow (spring), by May 2) · Swiss Chard (direct sow (spring), by May 2) · Celeriac (transplant outdoors, by May 5) · Celery (transplant outdoors, by May 5) · Oregano (transplant outdoors, by May 5) · Sage (transplant outdoors, by May 5) · Thyme (transplant outdoors, by May 5) · Dill (direct sow (spring), by May 9) · Sunflower (direct sow (spring), by May 9) · Ground Cherry (transplant outdoors, by May 12) · New Zealand Spinach (transplant outdoors, by May 12) · Peanut (transplant outdoors, by May 12) · Pumpkin (transplant outdoors, by May 12) · Rosemary (transplant outdoors, by May 12) · Shiso (Perilla) (transplant outdoors, by May 12) · Summer Savory (transplant outdoors, by May 12) · Sunflower (transplant outdoors, by May 12) · Sweet Marjoram (transplant outdoors, by May 12) · Tomatillo (transplant outdoors, by May 12) · Tomato (transplant outdoors, by May 12) · Winter Squash (transplant outdoors, by May 12) · Zucchini / Summer Squash (transplant outdoors, by May 12) · Amaranth (Leaf) (direct sow (spring), by May 16) · Bush Bean (direct sow (spring), by May 16) · Edamame (Soybean) (direct sow (spring), by May 16) · New Zealand Spinach (direct sow (spring), by May 16) · Pole Bean (direct sow (spring), by May 16) · Pumpkin (direct sow (spring), by May 16) · Shiso (Perilla) (direct sow (spring), by May 16) · Summer Savory (direct sow (spring), by May 16) · Sweet Corn (direct sow (spring), by May 16) · Sweet Marjoram (direct sow (spring), by May 16) · Winter Squash (direct sow (spring), by May 16) · Zucchini / Summer Squash (direct sow (spring), by May 16)
Sow or plant outdoors in May (64)
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 |
|---|---|---|---|
| Fennel (Bulb) | Direct sow (spring) | Apr 13 – May 2 | Last chance - ends May 2 |
| Lemon Balm | Direct sow (spring) | Apr 13 – May 2 | Last chance - ends May 2 |
| Parsnip | Direct sow (spring) | Apr 13 – May 2 | Last chance - ends May 2 |
| Swiss Chard | Direct sow (spring) | Apr 13 – May 2 | Last chance - ends May 2 |
| Celeriac | Transplant outdoors | Apr 18 – May 5 | Last chance - ends May 5 |
| Celery | Transplant outdoors | Apr 18 – May 5 | Last chance - ends May 5 |
| Oregano | Transplant outdoors | Apr 18 – May 5 | Last chance - ends May 5 |
| Sage | Transplant outdoors | Apr 18 – May 5 | Last chance - ends May 5 |
| Thyme | Transplant outdoors | Apr 18 – May 5 | Last chance - ends May 5 |
| Dill | Direct sow (spring) | Apr 20 – May 9 | Last chance - ends May 9 |
| Sunflower | Direct sow (spring) | Apr 20 – May 9 | Last chance - ends May 9 |
| Ground Cherry | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| New Zealand Spinach | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Peanut | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Pumpkin | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Rosemary | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Shiso (Perilla) | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Summer Savory | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Sunflower | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Sweet Marjoram | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Tomatillo | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Tomato | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Winter Squash | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Zucchini / Summer Squash | Transplant outdoors | Apr 25 – May 12 | Last chance - ends May 12 |
| Amaranth (Leaf) | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Bush Bean | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Edamame (Soybean) | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| New Zealand Spinach | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Pole Bean | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Pumpkin | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Shiso (Perilla) | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Summer Savory | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Sweet Corn | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Sweet Marjoram | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Winter Squash | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Zucchini / Summer Squash | Direct sow (spring) | Apr 27 – May 16 | Last chance - ends May 16 |
| Basil | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Bell Pepper | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Bitter Melon | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Cantaloupe / Muskmelon | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Chili Pepper | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Cucamelon | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Cucumber | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Luffa (Loofah Gourd) | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Malabar Spinach | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Okra | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Watermelon | Transplant outdoors | May 2 – May 19 | May 2 – May 19 |
| Basil | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Bitter Melon | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Cantaloupe / Muskmelon | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Chayote | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Cucamelon | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Cucumber | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Lima Bean | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Luffa (Loofah Gourd) | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Malabar Spinach | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Okra | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Peanut | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Southern Pea (Cowpea) | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Watermelon | Direct sow (spring) | May 4 – May 23 | May 4 – May 23 |
| Eggplant | Transplant outdoors | May 9 – May 26 | May 9 – May 26 |
| Ginger | Transplant outdoors | May 9 – May 26 | May 9 – May 26 |
| Sweet Potato | Transplant outdoors | May 9 – May 26 | May 9 – May 26 |
| Turmeric | Transplant outdoors | May 9 – May 26 | May 9 – 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 8 and May 20
- Lettuce: sow again on May 5 and May 17 and May 29
- Spinach: sow again on May 8 and May 20
- Carrot: sow again on May 10 and May 28
- Beet: sow again on May 3 and May 21
- Radish: sow again on May 7 and May 17 and May 27
- Cilantro / Coriander: sow again on May 17
- Arugula: sow again on May 3 and May 15 and May 27
- Turnip: sow again on May 2 and May 16 and May 30
- Kohlrabi: sow again on May 2 and May 16 and May 30
- Bok Choy / Pak Choi: sow again on May 9 and May 23
- Mustard Greens: sow again on May 2 and May 16 and May 30
- Green Onion / Scallion: sow again on May 9 and May 30
- Endive & Escarole: sow again on May 9 and May 23
- Mache (Corn Salad): sow again on May 2 and May 16 and May 30
- Rapini (Broccoli Raab): sow again on May 2 and May 16 and May 30
- Tatsoi: sow again on May 3 and May 15 and May 27
- Mizuna: sow again on May 3 and May 15 and May 27
- Chervil: sow again on May 2 and May 16 and May 30
- Watercress: sow again on May 2 and May 23
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 Connecticut
Every crop has its own full-year dates for Connecticut: indoor start, transplant or direct sowing, and harvest.
Main planting month: May garden jobs in Connecticut
- With the average last frost on April 25, 46 crops can go in outdoors this month, including fennel (bulb), lemon balm, parsnip, swiss chard.
- 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 Connecticut
Connecticut spans USDA zones 5b, 6a, 6b, 7a. 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 Connecticut in May?
66 crops have a window in May: fennel (bulb), lemon balm, parsnip, swiss chard, celeriac, celery, oregano, sage, thyme, dill and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Connecticut in May?
No - transplant outdoors runs Apr 25 – May 12 in Connecticut, so do it before May 12.
Is it too late to plant lettuce in Connecticut in May?
Not too late - it's actually a little early. In Connecticut the next lettuce window opens around August 10: sow for a fall crop.
When is the first frost in Connecticut?
The statewide average first fall frost is around October 15 and the last spring frost around April 25. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Connecticut in May?
From plantings made on time: spinach, arugula, tatsoi, mizuna, mustard greens, mache (corn salad), lettuce, turnip, rapini (broccoli raab), chervil.
What to plant in May in other states
Dates are computed from Connecticut’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.