Planting dates come from your frost dates, not your zone. A USDA zone is the average coldest winter night at your place, a guide to which perennials survive the winter. Two gardens in the same zone can have their last spring frost more than a month apart: in zone 8a, Atlanta’s averages March 15 and Olympia, Washington’s April 29. For the middle of zone 6, start tomato seeds indoors in mid-March, sow peas and spinach from late March and set tomatoes out from mid-May. In zone 7, each step comes about two weeks earlier. Type your ZIP code above for your own dates.
What your zone measures, and what it doesn’t
The USDA Plant Hardiness Zone Map is based on the average annual extreme minimum winter temperature: the coldest night of each winter, averaged over 1991 to 2020. Each zone spans 10 °F and is split into “a” and “b” halves of 5 °F (USDA). The USDA calls the map the standard for deciding which perennial plants are most likely to thrive at a place, and says its maps should serve as general guides for growing perennials. Look up yours with the zone finder.
The map says nothing about when the last frost of spring or the first frost of fall comes, and those are what decide when vegetables and annuals go in. Purdue Extension’s vegetable planting calendar, for one, sets its dates from the last spring frost and the first fall frost. The USDA itself notes that an early cold snap in fall can injure plants before temperatures reach the zone’s average low, something the map can’t take into account.
Same zone, weeks apart
These pairs share a half zone on the 2023 map. Their frost dates, from the NOAA weather station our ZIP lookup uses for each, are 31 to 45 days apart in spring, and their frost-free seasons differ by more than two months.
| Place | ZIP | Average last frost | Average first frost | Frost-free | NOAA station |
|---|---|---|---|---|---|
| Zone 6b: last frost 40 days apart | |||||
| Kansas City, MO | 64106 | Apr 4 | Nov 2 | 211 days | Kansas City Downtown AP, MO |
| Santa Fe, NM | 87501 | May 14 | Oct 6 | 144 days | Santa Fe 2, NM |
| Zone 7b: last frost 31 days apart | |||||
| New York, NY | 10001 | Mar 30 | Nov 20 | 236 days | New York Cntrl Pk Twr, NY |
| Prescott, AZ | 86301 | Apr 30 | Oct 20 | 172 days | Prescott, AZ |
| Zone 8a: last frost 45 days apart | |||||
| Atlanta, GA | 30303 | Mar 15 | Nov 20 | 252 days | Atlanta Hartsfield Intl AP, GA |
| Olympia, WA | 98501 | Apr 29 | Oct 14 | 169 days | Olympia AP, WA |
Average dates of the last and first 32 °F night, NOAA 1991–2020 normals. Frost-free: the days between them in at least half of years.
A zone follows the coldest night of the year; frost dates follow the first and last nights at 32 °F, and those also change over short distances. Cold air flows down into low spots (Penn State Extension), and the USDA warns of frost pockets too small to show on its map.
Typical planting calendar by zone
If all you know is your zone, here is the middle of the road: dates for the typical ZIP code in each zone, worked out with the same rules as our ZIP lookup. In half of a zone’s ZIP codes the dates come later than this, and in 1 in 10 they come about two weeks or more later, so check yours with the lookup above.
Start tomato seeds indoors Apr 5. Peas, spinach, onions, potatoes Apr 19 – May 3. Lettuce, carrots, beets May 3 – May 17. Tomatoes, beans, sweet corn from May 31. Peppers, squash, cucumbers from Jun 14. Fall lettuce, spinach, kale Jul 17 – Aug 14. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Mar 29. Peas, spinach, onions, potatoes Apr 13 – Apr 27. Lettuce, carrots, beets Apr 27 – May 11. Tomatoes, beans, sweet corn from May 25. Peppers, squash, cucumbers from Jun 8. Fall lettuce, spinach, kale Jul 23 – Aug 20. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Mar 21. Peas, spinach, onions, potatoes Apr 4 – Apr 18. Lettuce, carrots, beets Apr 18 – May 2. Tomatoes, beans, sweet corn from May 16. Peppers, squash, cucumbers from May 30. Fall lettuce, spinach, kale Jul 30 – Aug 27. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Mar 14. Peas, spinach, onions, potatoes Mar 30 – Apr 13. Lettuce, carrots, beets Apr 13 – Apr 27. Tomatoes, beans, sweet corn from May 11. Peppers, squash, cucumbers from May 25. Fall lettuce, spinach, kale Aug 9 – Sep 6. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Feb 27. Peas, spinach, onions, potatoes Mar 16 – Mar 30. Lettuce, carrots, beets Mar 30 – Apr 13. Tomatoes, beans, sweet corn from Apr 27. Peppers, squash, cucumbers from May 11. Fall lettuce, spinach, kale Aug 20 – Sep 17. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Feb 10. Peas, spinach, onions, potatoes Feb 27 – Mar 13. Lettuce, carrots, beets Mar 13 – Mar 27. Tomatoes, beans, sweet corn from Apr 10. Peppers, squash, cucumbers from Apr 24. Fall lettuce, spinach, kale Sep 2 – Sep 30. · Purdue, NDSU; dates from NOAA
Start tomato seeds indoors Jan 10. Peas, spinach, onions, potatoes Feb 3 – Feb 17. Lettuce, carrots, beets Feb 17 – Mar 3. Tomatoes, beans, sweet corn from Mar 17. Peppers, squash, cucumbers from Mar 31. Fall lettuce, spinach, kale Sep 19 – Oct 17. · Purdue, NDSU; dates from NOAAIn mild winters cool crops keep growing: Texas A&M AgriLife sows spinach and radishes around December 15 in its warmest region, which it pairs with zone 9b.
Only 25% of zone 10 ZIP codes have frost in most years, so a frost-based calendar doesn’t fit here. Use your ZIP code above, or your state’s Extension planting guide. · Our count from NOAA data
Typical: the median of each zone’s ZIP codes. Purdue’s rules count from the date a later spring frost comes only 1 year in 10, and fall crops from the date an earlier fall frost comes 1 year in 10; NDSU’s seed starting counts from the average last frost. How we worked it out is below.
Typical frost dates by zone
The typical date in each zone, and the range that holds 8 in 10 of its ZIP codes:
| Zone | ZIP codes counted | Typical last frost | 8 in 10 ZIP codes | Typical first frost | 8 in 10 ZIP codes |
|---|---|---|---|---|---|
| 3 | 223 | May 17 | May 12 – May 30 | Sep 24 | Sep 8 – Oct 1 |
| 4 | 2,013 | May 10 | May 2 – May 25 | Sep 30 | Sep 21 – Oct 7 |
| 5 | 5,220 | May 2 | Apr 23 – May 19 | Oct 7 | Sep 27 – Oct 18 |
| 6 | 10,399 | Apr 25 | Apr 13 – May 8 | Oct 20 | Oct 6 – Oct 28 |
| 7 | 8,718 | Apr 10 | Mar 31 – Apr 25 | Oct 29 | Oct 19 – Nov 9 |
| 8 | 6,683 | Mar 24 | Mar 8 – Apr 6 | Nov 10 | Nov 1 – Nov 20 |
| 9 | 4,091 | Feb 21 | Jan 20 – Mar 13 | Dec 3 | Nov 18 – Dec 28 |
| 10 | 506 | Only 25% of zone 10’s 1,986 ZIP codes have frost in most years; the rest have a freeze only in some winters, or none. | |||
Average dates of the last spring and first fall 32 °F night at each ZIP code’s NOAA station, 1991–2020. Zones 1 and 2 are only in Alaska; zones 11 to 13 have no freeze in most years.
Neighboring zones overlap. A typical zone 6 ZIP code has its last frost on April 25, and so does a late zone 7 one. A late zone 6 ZIP code (May 8) frosts later than a typical zone 5 one (May 2). Across 8 in 10 ZIP codes, the last frost spreads over about 3 to 4 weeks in zones 4 to 8, and more than 7 weeks in zone 9.
Warm zones: two seasons
In the warm zones the garden often runs on two seasons, and the cool one is winter. Texas A&M AgriLife sets a second crop of tomatoes out in summer for fall, from June 1 in the region it pairs with USDA zone 6 to August 1 in the one it pairs with zone 9b, and sows spinach and radishes there around December 15. In zone 10, only a quarter of ZIP codes have frost in most years, so a frost calendar doesn’t fit: your state Extension service’s vegetable planting guide gives dates by season.
How we worked it out
- Zones: the USDA’s 2023 map, by ZIP code, from the PRISM Group at Oregon State University.
- Frost dates: for each ZIP code, the NOAA weather station our lookup picks (named under every result), with its 1991–2020 normals: the average dates of the last 32 °F night in spring and the first in fall, and the dates frost beats only 1 year in 10.
- Typical dates: the median across a zone’s ZIP codes, each counted once, so towns and cities, with more ZIP codes, weigh more. The range is the middle 8 in 10. We left out ZIP codes whose station has no freeze in most years or a freeze only in some winters, frost in any month, or no frost records within 60 miles.
- Planting rules: Purdue Extension’s vegetable planting calendar puts hardy crops in 4 to 6 weeks before the last spring frost, semi-hardy crops 2 to 4 weeks before, tender crops after it, very tender crops at least two weeks after, and fall crops at least 4 to 8 weeks before the first fall frost. Its frost maps show the dates frost beats 1 year in 10, and we count every step from those, as our home-page planner does. Purdue times its tender crops from the average last frost, about two weeks earlier, so our dates for them err on the safe side. NDSU Extension starts tomato seeds indoors 6 weeks before the last frost; the seed starting calculator has the other crops.
Questions people ask
What is the planting schedule for zone 6?
For a typical zone 6 ZIP code (average last frost April 25): start tomato seeds indoors around March 14; plant peas, spinach, onions and potatoes March 30 to April 13; lettuce, carrots and beets April 13 to 27; tomatoes, beans and sweet corn from May 11; peppers, squash and cucumbers from May 25; and fall lettuce, spinach and kale August 9 to September 6. In 8 of 10 zone 6 ZIP codes the last frost falls between April 13 and May 8, so check yours.
What is the planting schedule for zone 7?
For a typical zone 7 ZIP code (average last frost April 10): tomato seeds indoors around February 27; peas, spinach, onions and potatoes March 16 to 30; lettuce, carrots and beets March 30 to April 13; tomatoes, beans and corn from April 27; peppers, squash and cucumbers from May 11; fall greens August 20 to September 17.
When should I plant tomatoes in my zone?
After your last spring frost: Purdue counts tomatoes as tender. From the date a later frost comes only 1 year in 10, that’s around May 16 in a typical zone 5 ZIP code, May 11 in zone 6, April 27 in zone 7, April 10 in zone 8 and March 17 in zone 9. Start the seeds indoors 6 weeks before your average last frost (NDSU); the seed starting calculator counts the date for your ZIP code.
When should I plant potatoes in zone 6 or 7?
Purdue lists potatoes with the hardy crops, 4 to 6 weeks before the last spring frost: about March 30 to April 13 in a typical zone 6 ZIP code, and March 16 to 30 in zone 7. In Texas, AgriLife also plants a fall crop, around August 1 in the region it pairs with zone 7.
When should I plant peas in zone 7?
Peas are hardy (Purdue): 6 to 4 weeks before the 1-in-10 last frost, about March 16 to 30 in a typical zone 7 ZIP code, and February 27 to March 13 in zone 8. The planting calendar on our home page gives your own pea dates by ZIP code.
When should I plant carrots and beets in zone 8?
Both are semi-hardy (Purdue): 4 to 2 weeks before the 1-in-10 last frost, about March 13 to 27 in a typical zone 8 ZIP code. Purdue sows beets again for fall, 8 to 4 weeks before the first frost: about September 2 to 30 in zone 8.
What can I plant in fall in zone 6?
Purdue’s fall list: beets, broccoli, Brussels sprouts (set out by midsummer), cabbage, collards, green onions, kale, kohlrabi, lettuce, mustard greens, radishes, spinach and turnips, planted at least 4 to 8 weeks before the first fall frost. That’s about August 9 to September 6 in a typical zone 6 ZIP code. Pick quick-maturing varieties for late plantings (Purdue).
Is my planting zone the same as my hardiness zone?
Yes: planting zone, growing zone and gardening zone all mean the USDA hardiness zone. Use it for perennials, shrubs and trees; for vegetables and annuals, go by your frost dates.
Sources
- USDA Agricultural Research Service, USDA Plant Hardiness Zone Map (2023): based on the average annual extreme minimum winter temperature, in 10 °F zones and 5 °F half zones; the standard for which perennial plants are most likely to thrive. How to Use the Maps: general guides for growing perennial plants; microclimates and frost pockets; an early-fall cold snap the map can’t take into account. USDA Unveils Updated Plant Hardiness Zone Map (November 15, 2023): weather data from 1991 to 2020.
- Zones by ZIP code: PRISM Group, Oregon State University, 2023 USDA Plant Hardiness Zone GIS Datasets, ZIP-code listings, prism.oregonstate.edu, accessed October 11, 2026.
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, freeze-date probabilities by station; ZIP code centers from the U.S. Census Bureau’s 2024 Gazetteer files. The medians and ranges by zone are our own count.
- Purdue Extension, Indiana Vegetable Planting Calendar (HO-186-W, Rosie Lerner, 2020): dates from the last spring and first fall frost; hardy crops 4–6 weeks before the last frost, semi-hardy 2–4 weeks before, tender after the average last frost, very tender at least 2 weeks after; fall crops at least 4–8 weeks before the first frost; frost maps at 1 year in 10, the 50% date about two weeks earlier in spring and later in fall.
- NDSU Extension, Time and Temperature Chart (H-1139): tomato seeds 6 weeks before the last frost date.
- Texas A&M AgriLife Extension, Fall Vegetable Gardening Guide for Texas (Larry Stein and Joe Masabni): fall planting dates by region (tomatoes June 1 to August 1; spinach and radishes December 15 in Region V; potatoes August 1 in Region II) and the regions’ USDA zones.
- Penn State Extension, Frost, Critical Temperatures, and Frost Protection (Rob Crassweller; updated March 18, 2024): cold air flows down to low areas.