When to plant / Tomatoes
When to plant tomatoes
Plant tomatoes 2 to 4 weeks after the last spring frost. Tomatoes are a very tender crop in Colorado State University Extension's planting guide, and that is the guide's rule for the class. Across the 39 U.S. cities on this site the window opens between Feb 23 (Sacramento, CA) and May 27 (Concord, NH), because each city's own NOAA last-frost date is different.
The planting rule for tomatoes, in plain words
Colorado State's Vegetable Planting Guide sorts vegetables into four frost classes and gives each class one timing rule relative to the average last spring frost. Tomatoes sit in the very tender class, whose rule reads: Typically 2+ weeks after the average last spring frost date.
On this site that becomes 2 to 4 weeks from the station's 50% probability last 32°F date, the same arithmetic every city calendar uses.
Tomatoes are normally transplanted, not direct-sown. The guide gives a transplant age of 5 to 7 weeks, so the indoor sowing window is the outdoor window moved back by that much; when to start seeds indoors walks through the subtraction. Typical days to harvest from transplanting: 65.
Soil temperature for tomatoes
Minimum soil temperature for tomatoes in the cited sources: 50°F (minimum germination soil temperature; a separate Colorado State PlantTalk page suggests 60°F to 65°F soil for setting out transplants). A frost date cannot see the soil, so take a morning reading before trusting the window; the soil temperature guide covers every crop.
Tomatoes: planting dates for 39 U.S. cities
The rule above applied to each station's own NOAA normals, earliest first. City links open that station's full calendar.
| City | Last spring frost (32°F) | Start seeds indoors | Transplant | Last fall planting |
|---|---|---|---|---|
| Sacramento, CA | Feb 9 | Jan 5 – Feb 2 | Feb 23 – Mar 9 | Sep 29 |
| Houston, TX | Feb 18 | Jan 14 – Feb 11 | Mar 4 – Mar 18 | Oct 4 |
| Austin, TX | Feb 19 | Jan 15 – Feb 12 | Mar 5 – Mar 19 | Oct 2 |
| San Antonio, TX | Mar 1 | Jan 25 – Feb 22 | Mar 15 – Mar 29 | Sep 27 |
| Dallas–Fort Worth, TX | Mar 8 | Feb 1 – Mar 1 | Mar 22 – Apr 5 | Sep 21 |
| Seattle, WA | Mar 8 | Feb 1 – Mar 1 | Mar 22 – Apr 5 | Sep 17 |
| Portland, OR | Mar 16 | Feb 9 – Mar 9 | Mar 30 – Apr 13 | Sep 13 |
| Atlanta, GA | Mar 20 | Feb 13 – Mar 13 | Apr 3 – Apr 17 | Sep 17 |
| Birmingham, AL | Mar 27 | Feb 20 – Mar 20 | Apr 10 – Apr 24 | Sep 8 |
| Oklahoma City, OK | Mar 27 | Feb 20 – Mar 20 | Apr 10 – Apr 24 | Sep 5 |
| Washington, DC | Mar 28 | Feb 21 – Mar 21 | Apr 11 – Apr 25 | Sep 13 |
| New York City | Apr 1 | Feb 25 – Mar 25 | Apr 15 – Apr 29 | Sep 14 |
| Philadelphia, PA | Apr 2 | Feb 26 – Mar 26 | Apr 16 – Apr 30 | Sep 6 |
| Louisville, KY | Apr 3 | Feb 27 – Mar 27 | Apr 17 – May 1 | Aug 31 |
| Raleigh, NC | Apr 3 | Feb 27 – Mar 27 | Apr 17 – May 1 | Aug 31 |
| St. Louis, MO | Apr 3 | Feb 27 – Mar 27 | Apr 17 – May 1 | Aug 30 |
| Charlotte, NC | Apr 4 | Feb 28 – Mar 28 | Apr 18 – May 2 | Aug 30 |
| Richmond, VA | Apr 4 | Feb 28 – Mar 28 | Apr 18 – May 2 | Aug 31 |
| Boston, MA | Apr 6 | Mar 2 – Mar 30 | Apr 20 – May 4 | Sep 4 |
| Nashville, TN | Apr 6 | Mar 2 – Mar 30 | Apr 20 – May 4 | Aug 29 |
| Kansas City, MO | Apr 12 | Mar 8 – Apr 5 | Apr 26 – May 10 | Aug 19 |
| Columbus, OH | Apr 16 | Mar 12 – Apr 9 | Apr 30 – May 14 | Aug 23 |
| Indianapolis, IN | Apr 16 | Mar 12 – Apr 9 | Apr 30 – May 14 | Aug 18 |
| Des Moines, IA | Apr 17 | Mar 13 – Apr 10 | May 1 – May 15 | Aug 13 |
| Detroit, MI | Apr 20 | Mar 16 – Apr 13 | May 4 – May 18 | Aug 20 |
| Omaha, NE | Apr 21 | Mar 17 – Apr 14 | May 5 – May 19 | Aug 7 |
| Salt Lake City, UT | Apr 21 | Mar 17 – Apr 14 | May 5 – May 19 | Aug 20 |
| Chicago, IL | Apr 22 | Mar 18 – Apr 15 | May 6 – May 20 | Aug 15 |
| Cleveland, OH | Apr 22 | Mar 18 – Apr 15 | May 6 – May 20 | Aug 27 |
| Hartford, CT | Apr 24 | Mar 20 – Apr 17 | May 8 – May 22 | Aug 9 |
| Pittsburgh, PA | Apr 24 | Mar 20 – Apr 17 | May 8 – May 22 | Aug 16 |
| Minneapolis, MN | Apr 25 | Mar 21 – Apr 18 | May 9 – May 23 | Aug 6 |
| Albany, NY | Apr 28 | Mar 24 – Apr 21 | May 12 – May 26 | Aug 6 |
| Grand Rapids, MI | Apr 28 | Mar 24 – Apr 21 | May 12 – May 26 | Aug 12 |
| Portland, ME | May 1 | Mar 27 – Apr 24 | May 15 – May 29 | Aug 6 |
| Madison, WI | May 2 | Mar 28 – Apr 25 | May 16 – May 30 | Aug 1 |
| Burlington, VT | May 4 | Mar 30 – Apr 27 | May 18 – Jun 1 | Aug 4 |
| Denver, CO | May 6 | Apr 1 – Apr 29 | May 20 – Jun 3 | Aug 2 |
| Concord, NH | May 13 | Apr 8 – May 6 | May 27 – Jun 10 | Jul 27 |
Fall column: 65 days to harvest counted back from the first fall 32°F date (Purdue HO-66-W method, methodology).
3 frost-free stations are left out. Not in the table? The planner takes any pair of frost dates.
Three cities, one rule
- Sacramento, California — last spring frost Feb 9, so transplant Feb 23 – Mar 9; start seeds indoors Jan 5 – Feb 2. 297 frost-free days in all.
- Kansas City, Missouri — last spring frost Apr 12, so transplant Apr 26 – May 10; start seeds indoors Mar 8 – Apr 5. 194 frost-free days in all.
- Concord, New Hampshire — last spring frost May 13, so transplant May 27 – Jun 10; start seeds indoors Apr 8 – May 6. 140 frost-free days in all.
Questions about planting tomatoes
When should I plant tomatoes outside?
Tomatoes are a very tender crop, so Colorado State Extension's rule is 2 to 4 weeks after the last spring frost. In Sacramento, CA that is Feb 23 – Mar 9; in Concord, NH it is May 27 – Jun 10. Find your city in the table above, or enter your own frost date in the planner.
When should I start seeds for tomatoes indoors?
Subtract the transplant age Colorado State publishes, 5 to 7 weeks, from the outdoor window. In Sacramento, CA that gives Jan 5 – Feb 2; in Concord, NH, Apr 8 – May 6.
What soil temperature do tomatoes need?
The minimum germination soil temperature in Colorado State Extension's guide is 50°F. The frost window is the earliest the crop is safe from freezing; the soil reading tells you whether it will actually grow. Measure at 4 inches in the morning before planting.
How long do tomatoes take to harvest?
Colorado State's typical days to harvest for this row is 65 days, counted from transplanting. Compare that to your city's frost-free days in the table: Sacramento, CA has 297, Concord, NH has 140.
Can I plant tomatoes for a fall harvest?
39 of the 39 cities in the table show a separate fall planting date for tomatoes, found by counting the days to harvest back from the first fall frost. Where the row says no separate fall sowing, the spring window already covers the season.
Related planting dates
- When to plant peppers — 2 to 4 weeks after the last spring frost
- When to plant cucumbers — from the last spring frost date to 1 week after it
- When to plant zucchini — from the last spring frost date to 1 week after it
- All crops · calendars by city · cool-season vs warm-season crops
Sources for this page
| Source | Used for | Read |
|---|---|---|
| NOAA/NCEI U.S. Climate Normals 1991–2020 | 50% probability last spring and first fall 32°F and 28°F dates for each station | 2026-10-16 |
| Colorado State University Extension, CMG GardenNotes #720 Vegetable Planting Guide | spring class rules, transplant age and days to harvest, via crops.json | 2026-10-16 |
| Colorado State University Extension, Vegetable Planting Guide (germination soil temperature table) | figures as quoted in this site's soil-temperature guide (/blog/soil-temperature-for-planting-vegetables/); the page could not be re-fetched on 2026-10-23 and the 2026-10-17 reading stands; the same minimum germination figures (tomato 50, pepper 60, potato 45, onion 35, cucumber and summer squash 60°F, read at 8 a.m. at 4 inches) appear in the soil temperature table of CMG GardenNotes #720, re-read 2026-10-23 | 2026-10-17 |
Every date in the table is arithmetic on the station's NOAA normal and the offset stated by the source; the quoted sentences are the only figures on this page that are not computed. Normals are 30-year averages and describe the station, not your yard. Rules checked 2026-10-23; see the methodology page.