When to plant tomatoes in New Hampshire
New Hampshire’s average last spring frost is May 13, and the first fall frost typically arrives around September 25 — about 135 frost-free days (USDA zones 3b, 4a, 4b, 5a, 5b, 6a). Tomato needs 60–85 days to mature, which fits comfortably within New Hampshire's growing season.
When to plant tomatoes in New Hampshire: the short answer
For a spring planting, plant out May 13 – May 30, with seeds started indoors Mar 18 – Apr 1. 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 New Hampshire, step by step
- Start seeds indoors (Mar 18 – Apr 1). 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 (May 13 – May 30). 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 Jul 19 – Aug 13). 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 New Hampshire’s average frost dates. More in the full tomato growing guide.
Tomato planting dates by USDA zone in New Hampshire
New Hampshire 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, so the tomato dates shift with them.
When to plant tomatoes in nearby states
| State | Last frost | Plant out |
|---|---|---|
| New Hampshire (this page) | May 13 | May 13 – May 30 |
| Maine | May 14 | May 14 – May 31 |
| Vermont | May 14 | May 14 – May 31 |
| Massachusetts | April 24 | Apr 24 – May 11 |
| Rhode Island | April 25 | Apr 25 – May 12 |
| Connecticut | April 25 | Apr 25 – May 12 |
| New York | May 1 | May 1 – May 18 |
Questions gardeners in New Hampshire ask
When is the best time to plant tomatoes in New Hampshire?
Plant tomato transplants outdoors in New Hampshire between May 13 and May 30. That timing is set by New Hampshire's average last spring frost of May 13.
When should I start tomato seeds indoors in New Hampshire?
Start seeds indoors between March 18 and April 1, about 7 weeks before the last frost, so the seedlings are ready to plant out from May 13.
What is the latest I can plant tomatoes in New Hampshire?
About July 27. Tomatoes need at least 60 days to mature after transplanting, and frost around September 25 ends the season, so later plantings risk being cut short.
When will tomatoes planted in New Hampshire be ready to harvest?
Planted on time, tomatoes are usually ready from about July 19 to August 13, 60-85 days after transplanting.
When is the last frost in New Hampshire?
On average around May 13, with the first fall frost around September 25 - about 135 frost-free days. Your town may differ by two weeks or more.