Wilmington, Delaware planting calendar and frost dates
Wilmington is in USDA hardiness zone 7b. The last spring frost typically comes around April 7 and the first fall frost around November 4, giving about 209 frost-free days a year.
- Hardiness zone
- Zone 7b
- Typical last frost
- April 7
- Typical first frost
- November 4
- Frost-free season
- 209 days
Frost dates in Wilmington
Last spring frost
- March 26Risky: frost later than this in 9 years out of 10
- April 7Typical: a later frost in half of years
- April 24Safe: a later frost only 1 year in 10
First fall frost
- October 21Risky: frost earlier than this 1 year in 10
- November 4Typical: an earlier frost in half of years
- November 19Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 209 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around March 29 and returns around November 15.
NOAA U.S. Climate Normals 1991-2020 for Wilmington Porter Rsch, 1.9 miles N of the city center and 179 feet higher. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.
What to plant each month in Wilmington
January
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons
February
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, cilantro, collard greens, ginger, kale, leeks, lettuce, marigolds, nasturtiums, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard
Plant or sow outdoors: black-eyed susans, blueberries, garlic, grapes, grass seed, hollyhocks, onions, peas, poppies, raspberries, rhubarb, strawberries, turnips, wildflowers
March
Start indoors: basil, celery, cilantro, eggplants, ginger, marigolds, nasturtiums, peppers, ranunculus, spinach, swiss chard, tomatoes
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, snapdragons, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, carrots, chives, cilantro, dahlias, dill, figs, garden mums, ginger, gladioli, grapes, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, perennial ryegrass, petunias, potatoes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme
May
Start indoors: cosmos, okra, zinnias
Plant or sow outdoors: asparagus, basil, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, garden mums, ginger, green beans, green onions, kentucky bluegrass, okra, peanuts, peppers, perennial ryegrass, pumpkins, st. augustinegrass, sunflowers, sweet peas, sweet potatoes, tall fescue, tomatoes, watermelons, winter squash, zoysiagrass, zucchini
June
Plant or sow outdoors: bermudagrass, celery, centipedegrass, cosmos, green onions, okra, peanuts, st. augustinegrass, sweet potatoes, zinnias, zoysiagrass
July
Plant or sow outdoors: bermudagrass, centipedegrass, zoysiagrass
Plant for fall: brussels sprouts
August
Plant for fall: bearded irises, beets, broccoli, brussels sprouts, cabbages, carrots, cauliflower, collard greens, lettuce, peas, radishes, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hydrangeas, kale, kentucky bluegrass, lettuce, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, roses, saffron, snapdragons, spinach, swiss chard, tall fescue, tulips, turnips
October
Plant for fall: crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, kale, kentucky bluegrass, lilies, ornamental alliums, peonies, perennial ryegrass, radishes, saffron, tall fescue, tulips
November
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
December
Start indoors: onions
Frost dates and zones by ZIP code in Wilmington
All 5 of Wilmington's main ZIP codes take their frost dates from Wilmington Porter Rsch, so the dates on this page apply across the city. Every one of them is in zone 7b.
| ZIP code | Zone | Weather station | Typical last frost | Typical first frost |
|---|---|---|---|---|
| 19801 | 7b | Wilmington Porter Rsch, 1.9 mi N | Apr 7 | Nov 4 |
| 19802 | 7b | Wilmington Porter Rsch, 1.9 mi N | Apr 7 | Nov 4 |
| 19805 | 7b | Wilmington Porter Rsch, 1.9 mi N | Apr 7 | Nov 4 |
| 19806 | 7b | Wilmington Porter Rsch, 1.9 mi N | Apr 7 | Nov 4 |
| 19809 | 7b | Wilmington Porter Rsch, 1.9 mi N | Apr 7 | Nov 4 |
Planting dates for popular crops in Wilmington
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 16 to 30 | May 11 to 25 | — |
| Strawberries | — | Feb 24 to Mar 10 | — |
| Lettuce | Feb 10 to 24 | Mar 31 to Apr 14 | Aug 5 to Sep 9 |
| Cilantro | Feb 24 to Mar 10 | Apr 7 to 14 | — |
| Basil | Mar 23 to Apr 6 | May 11 to 18 | — |
| Potatoes | — | Apr 11 to 18 | — |
| Garlic | — | Feb 24 to Mar 10 | Nov 4 to 18 |
| Onions | Dec 16 to Jan 27 | Mar 10 to 24 | — |
| Cucumbers | Apr 13 to 27 | May 11 to 25 | — |
| Pumpkins | Apr 13 to 27 | May 11 to 25 | — |
| Peppers | Feb 23 to Mar 23 | May 11 to 25 | — |
| Carrots | — | Mar 17 to Apr 7 | Aug 12 to Sep 2 |
| Sweet Potatoes | — | May 29 to Jun 5 | — |
| Watermelons | Apr 6 to 20 | May 11 to 25 | — |
| Sweet Corn | — | Apr 11 to 25 | — |
| Green Beans | — | May 11 to 25 | — |
| Zucchini | Apr 13 to 27 | May 11 to 25 | — |
| Broccoli | Jan 20 to Feb 10 | Mar 10 to 24 | Aug 19 to Sep 16 |
| Peas | — | Feb 24 to Mar 10 | Aug 12 to 26 |
| Spinach | Feb 24 to Mar 3 | Mar 31 to Apr 14 | Aug 26 to Sep 30 |
| Sunflowers | — | Apr 11 to May 2 | — |
| Zinnias | May 17 to 24 | Jun 14 to 28 | — |
| Tulips | — | — | Sep 23 to Nov 18 |
| Daffodils | — | — | Sep 23 to Nov 4 |
| Grass Seed | — | Feb 24 to Mar 10 | Sep 23 to Oct 7 |
Nearby cities
- Camden, NJ zone 7b, last frost Apr 2
- Philadelphia, PA zone 7b, last frost Mar 30
- Vineland, NJ zone 7a, last frost Apr 24
- Lancaster, PA zone 7a, last frost Apr 19
- Reading, PA zone 7a, last frost Apr 14
- Trenton, NJ zone 7b, last frost Apr 10
Planting in DelawareAbout zone 7bPrintable calendar for Wilmington
Questions
When is the last frost in Wilmington?
Around April 7 in a typical year, based on NOAA's 1991-2020 records for Wilmington Porter Rsch. There is still a 1 in 10 chance of frost after April 24.
What planting zone is Wilmington in?
USDA hardiness zone 7b (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Wilmington?
Start seeds indoors March 16 to 30 and set plants out May 11 to 25.
When is the first frost in Wilmington?
Around November 4 in a typical year, and before October 21 about 1 year in 10.