What to plant in May in Delaware
In Delaware (DE), May comes about 4 weeks after the average last frost (April 14). The state averages 191 frost-free days a year (last frost April 14, first frost October 22; USDA zones 7a, 7b).
58 crops have a sowing or planting window this month, including ground cherry, new zealand spinach, peanut, pumpkin, rosemary, shiso (perilla) - and 53 of those windows close during May.
Dates here come from Delaware frost dates (last frost Apr 14, first frost Oct 22). For one crop in detail, see when to plant pumpkin, tomato or winter squash in Delaware.
Delaware: planting activity through the year
Last chance in May
Ground Cherry (transplant outdoors, by May 1) · New Zealand Spinach (transplant outdoors, by May 1) · Peanut (transplant outdoors, by May 1) · Pumpkin (transplant outdoors, by May 1) · Rosemary (transplant outdoors, by May 1) · Shiso (Perilla) (transplant outdoors, by May 1) · Summer Savory (transplant outdoors, by May 1) · Sunflower (transplant outdoors, by May 1) · Sweet Marjoram (transplant outdoors, by May 1) · Tomatillo (transplant outdoors, by May 1) · Tomato (transplant outdoors, by May 1) · Winter Squash (transplant outdoors, by May 1) · Zucchini / Summer Squash (transplant outdoors, by May 1) · Amaranth (Leaf) (direct sow (spring), by May 5) · Bush Bean (direct sow (spring), by May 5) · Edamame (Soybean) (direct sow (spring), by May 5) · New Zealand Spinach (direct sow (spring), by May 5) · Pole Bean (direct sow (spring), by May 5) · Pumpkin (direct sow (spring), by May 5) · Shiso (Perilla) (direct sow (spring), by May 5) · Summer Savory (direct sow (spring), by May 5) · Sweet Corn (direct sow (spring), by May 5) · Sweet Marjoram (direct sow (spring), by May 5) · Winter Squash (direct sow (spring), by May 5) · Zucchini / Summer Squash (direct sow (spring), by May 5) · Basil (transplant outdoors, by May 8) · Bell Pepper (transplant outdoors, by May 8) · Bitter Melon (transplant outdoors, by May 8) · Cantaloupe / Muskmelon (transplant outdoors, by May 8) · Chili Pepper (transplant outdoors, by May 8) · Cucamelon (transplant outdoors, by May 8) · Cucumber (transplant outdoors, by May 8) · Luffa (Loofah Gourd) (transplant outdoors, by May 8) · Malabar Spinach (transplant outdoors, by May 8) · Okra (transplant outdoors, by May 8) · Watermelon (transplant outdoors, by May 8) · Basil (direct sow (spring), by May 12) · Bitter Melon (direct sow (spring), by May 12) · Cantaloupe / Muskmelon (direct sow (spring), by May 12) · Chayote (direct sow (spring), by May 12) · Cucamelon (direct sow (spring), by May 12) · Cucumber (direct sow (spring), by May 12) · Lima Bean (direct sow (spring), by May 12) · Luffa (Loofah Gourd) (direct sow (spring), by May 12) · Malabar Spinach (direct sow (spring), by May 12) · Okra (direct sow (spring), by May 12) · Peanut (direct sow (spring), by May 12) · Southern Pea (Cowpea) (direct sow (spring), by May 12) · Watermelon (direct sow (spring), by May 12) · Eggplant (transplant outdoors, by May 15) · Ginger (transplant outdoors, by May 15) · Sweet Potato (transplant outdoors, by May 15) · Turmeric (transplant outdoors, by May 15)
Sow or plant outdoors in May (53)
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 |
|---|---|---|---|
| Ground Cherry | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| New Zealand Spinach | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Peanut | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Pumpkin | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Rosemary | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Shiso (Perilla) | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Summer Savory | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Sunflower | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Sweet Marjoram | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Tomatillo | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Tomato | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Winter Squash | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Zucchini / Summer Squash | Transplant outdoors | Apr 14 – May 1 | Last chance - ends May 1 |
| Amaranth (Leaf) | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Bush Bean | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Edamame (Soybean) | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| New Zealand Spinach | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Pole Bean | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Pumpkin | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Shiso (Perilla) | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Summer Savory | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Sweet Corn | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Sweet Marjoram | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Winter Squash | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Zucchini / Summer Squash | Direct sow (spring) | Apr 16 – May 5 | Last chance - ends May 5 |
| Basil | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Bell Pepper | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Bitter Melon | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Cantaloupe / Muskmelon | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Chili Pepper | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Cucamelon | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Cucumber | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Luffa (Loofah Gourd) | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Malabar Spinach | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Okra | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Watermelon | Transplant outdoors | Apr 21 – May 8 | Last chance - ends May 8 |
| Basil | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Bitter Melon | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Cantaloupe / Muskmelon | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Chayote | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Cucamelon | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Cucumber | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Lima Bean | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Luffa (Loofah Gourd) | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Malabar Spinach | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Okra | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Peanut | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Southern Pea (Cowpea) | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Watermelon | Direct sow (spring) | Apr 23 – May 12 | Last chance - ends May 12 |
| Eggplant | Transplant outdoors | Apr 28 – May 15 | Last chance - ends May 15 |
| Ginger | Transplant outdoors | Apr 28 – May 15 | Last chance - ends May 15 |
| Sweet Potato | Transplant outdoors | Apr 28 – May 15 | Last chance - ends May 15 |
| Turmeric | Transplant outdoors | Apr 28 – May 15 | Last chance - ends May 15 |
Keep sowing (succession)
Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.
- Pea: sow again on May 9
- Lettuce: sow again on May 6 and May 18
- Spinach: sow again on May 9
- Carrot: sow again on May 17
- Beet: sow again on May 10
- Radish: sow again on May 6 and May 16
- Cilantro / Coriander: sow again on May 6
- Dill: sow again on May 5
- Arugula: sow again on May 4 and May 16
- Turnip: sow again on May 5 and May 19
- Kohlrabi: sow again on May 5 and May 19
- Bok Choy / Pak Choi: sow again on May 12
- Mustard Greens: sow again on May 5 and May 19
- Green Onion / Scallion: sow again on May 19
- Fennel (Bulb): sow again on May 19
- Endive & Escarole: sow again on May 12
- Mache (Corn Salad): sow again on May 5 and May 19
- Rapini (Broccoli Raab): sow again on May 5 and May 19
- Tatsoi: sow again on May 4 and May 16
- Mizuna: sow again on May 4 and May 16
- Chervil: sow again on May 5 and May 19
- Watercress: sow again on May 12
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 Delaware
Every crop has its own full-year dates for Delaware: indoor start, transplant or direct sowing, and harvest.
Main planting month: May garden jobs in Delaware
- With the average last frost on April 14, 36 crops can go in outdoors this month, including ground cherry, new zealand spinach, peanut, pumpkin.
- 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).
Questions gardeners ask
What vegetables can I plant in Delaware in May?
58 crops have a window in May: ground cherry, new zealand spinach, peanut, pumpkin, rosemary, shiso (perilla), summer savory, sunflower, sweet marjoram, tomatillo and more. The tables above give the exact dates for each.
Is it too late to plant tomatoes in Delaware in May?
No - transplant outdoors runs Apr 14 – May 1 in Delaware, so do it before May 1.
Is it too late to plant lettuce in Delaware in May?
Not too late - it's actually a little early. In Delaware the next lettuce window opens around August 17: sow for a fall crop.
When is the first frost in Delaware?
The statewide average first fall frost is around October 22 and the last spring frost around April 14. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Delaware in May?
From plantings made on time: tatsoi, mizuna, mustard greens, mache (corn salad), lettuce, turnip, rapini (broccoli raab), chervil, pea, bok choy / pak choi.
What to plant in May in other states
Dates are computed from Delaware’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.