When to plant tomatoes in Delaware
Delaware’s average last spring frost is April 14, and the first fall frost typically arrives around October 22 — about 191 frost-free days (USDA zones 7a, 7b). Tomato needs 60–85 days to mature, which fits comfortably within Delaware's growing season.
When to plant tomatoes in Delaware: the short answer
For a spring planting, plant out Apr 14 – May 1, with seeds started indoors Feb 17 – Mar 3. Wait until the soil is at least 50°F and frost is over.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow tomatoes in Delaware, step by step
- Start seeds indoors (Feb 17 – Mar 3). Sow seeds ¼ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 80°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 5.5 and 7.5. Dig in compost before planting.
- Plant out (Apr 14 – May 1). Space plants about 24 inches apart in rows 36 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: tomato hornworm, aphids, whitefly, flea beetle. Diseases and disorders: early blight, late blight, septoria leaf spot, fusarium wilt, blossom-end rot (calcium disorder).
- Harvest (from about Jun 20 – Jul 15). Tomato takes 60-85 days to reach harvest. Days to maturity counted from transplant. Bury 2/3 of the stem at transplanting for extra roots. Determinate types suit containers and one big harvest; indeterminate types need staking and produce until frost.
Figures come from our crop data; dates use Delaware’s average frost dates. More in the full tomato growing guide.
When to plant tomatoes in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Delaware (this page) | April 14 | Apr 14 – May 1 |
| New Jersey | April 20 | Apr 20 – May 7 |
| Pennsylvania | May 1 | May 1 – May 18 |
| Maryland | April 14 | Apr 14 – May 1 |
| District of Columbia | April 10 | Apr 10 – Apr 27 |
| Virginia | April 15 | Apr 15 – May 2 |
| West Virginia | May 5 | May 5 – May 22 |
Questions gardeners in Delaware ask
When is the best time to plant tomatoes in Delaware?
Plant tomato transplants outdoors in Delaware between April 14 and May 1. That timing is set by Delaware's average last spring frost of April 14.
When should I start tomato seeds indoors in Delaware?
Start seeds indoors between February 17 and March 3, about 7 weeks before the last frost, so the seedlings are ready to plant out from April 14.
What is the latest I can plant tomatoes in Delaware?
About August 23. Tomatoes need at least 60 days to mature after transplanting, and frost around October 22 ends the season, so later plantings risk being cut short.
When will tomatoes planted in Delaware be ready to harvest?
Planted on time, tomatoes are usually ready from about June 20 to July 15, 60-85 days after transplanting.
When is the last frost in Delaware?
On average around April 14, with the first fall frost around October 22 - about 191 frost-free days. Your town may differ by two weeks or more.