The four dates that matter
| Date | When | What it means |
|---|---|---|
| Last spring frost (50%) | Apr 13 | Half of all years see a freeze after this date. It is an average, not a guarantee. |
| Last spring frost (10%) | Apr 28 | Only one year in ten freezes after this. Use it for anything you cannot afford to replant. |
| First fall frost (50%) | Oct 30 | Half of all years freeze before this date. Fall crops are counted back from here. |
| First fall frost (10%) | Oct 16 | An early-freeze year. If a crop must finish, aim to harvest before this. |
Spring & summer planting in Roswell
Dates are calculated from this location's own last-frost date, not from a generic zone chart. โBest moon daysโ are the days inside each window that fall in the crop's traditional phase โ the same rule the app uses.
| Crop | Start seed indoors | Plant outdoors | Best moon days | Days to harvest |
|---|---|---|---|---|
| Strawberry (crowns) transplant |
โ | Feb 12 โ Mar 23 | Mar 3 Full Moon |
perennial โ first real harvest next season |
| Garlic cloves/sets Better planted in fall โ see below |
โ | Feb 25 โ Mar 28 | Mar 4โ9 Waning Gibbous |
240โ300 |
| Asparagus (crowns) transplant |
โ | Mar 2 โ Apr 6 | Mar 25 First Quarter |
perennial โ first real harvest 2โ3 years |
| Chives either |
Feb 16 | Mar 2 โ Apr 6 | Mar 19โ24 Waxing Crescent |
75โ90 |
| Onion (from sets/transplants) cloves/sets |
โ | Mar 2 โ Apr 6 | Mar 4โ9 Waning Gibbous |
90โ120 |
| Peas (English/snap) direct sow |
โ | Mar 2 โ Apr 6 | Mar 25 First Quarter |
55โ75 |
| Spinach direct sow |
โ | Mar 2 โ Apr 6 | Mar 19โ24 Waxing Crescent |
35โ50 |
| Cabbage transplant |
Feb 9 | Mar 9 โ Apr 6 | Mar 19โ24 Waxing Crescent |
65โ90 |
| Collards either |
Mar 2 | Mar 9 โ Apr 27 | Mar 19โ24 Waxing Crescent |
55โ85 |
| Kale either |
Mar 2 | Mar 9 โ Apr 13 | Mar 19โ24 Waxing Crescent |
50โ65 |
| Lettuce (leaf) either |
Mar 9 | Mar 9 โ May 4 | Mar 19โ24 Waxing Crescent |
40โ55 |
| Potato cloves/sets |
โ | Mar 9 โ Apr 13 | Apr 1 Full Moon |
70โ120 |
| Radish direct sow |
โ | Mar 9 โ May 4 | Mar 9โ10, Apr 2โ5 Waning Gibbous |
22โ35 |
| Turnip direct sow |
โ | Mar 9 โ Apr 20 | Mar 9โ10, Apr 2โ5 Waning Gibbous |
40โ60 |
| Broccoli transplant |
Feb 9 | Mar 14 โ Apr 13 | Mar 19โ24 Waxing Crescent |
55โ80 |
| Brussels Sprouts transplant |
Feb 9 | Mar 14 โ Apr 13 | Mar 19โ24 Waxing Crescent |
90โ110 |
| Leek transplant |
Feb 2 | Mar 14 โ Apr 13 | Apr 2โ7 Waning Gibbous |
100โ120 |
| Lettuce (head) transplant |
Feb 23 | Mar 14 โ Apr 13 | Mar 19โ24 Waxing Crescent |
60โ85 |
| Parsley either |
Feb 9 | Mar 14 โ Apr 20 | Mar 19โ24 Waxing Crescent |
70โ90 |
| Parsnip direct sow |
โ | Mar 14 โ Apr 20 | Apr 1 Full Moon |
100โ150 |
| Shallot cloves/sets Better planted in fall โ see below |
โ | Mar 14 โ Apr 13 | Apr 2โ7 Waning Gibbous |
90โ120 |
| Beet direct sow |
โ | Mar 16 โ May 4 | Apr 1, May 1 Full Moon |
50โ65 |
| Kohlrabi either |
Mar 2 | Mar 16 โ Apr 20 | Mar 19โ24 Waxing Crescent |
45โ60 |
| Carrot direct sow |
โ | Mar 23 โ May 4 | Apr 1, May 1 Full Moon |
65โ85 |
| Cauliflower transplant |
Feb 9 | Mar 23 โ Apr 13 | Mar 23โ24 Waxing Crescent |
55โ80 |
| Cilantro direct sow |
โ | Mar 23 โ May 4 | Mar 23โ24, Apr 18โ21 Waxing Crescent |
45โ70 |
| Swiss Chard direct sow |
โ | Mar 23 โ May 13 | Mar 23โ24, Apr 18โ21 Waxing Crescent |
50โ60 |
| Dill direct sow |
โ | Mar 30 โ May 13 | Apr 18โ22 Waxing Crescent |
40โ60 |
| Cucumber either |
Mar 23 | Apr 13 โ May 13 | Apr 23 First Quarter |
50โ70 |
| Green Beans (bush) direct sow |
โ | Apr 13 โ May 28 | Apr 23, May 23 First Quarter |
50โ65 |
| Oregano transplant |
Feb 16 | Apr 13 โ May 4 | Apr 23 First Quarter |
cut as needed |
| Sage transplant |
Feb 16 | Apr 13 โ May 4 | Apr 23 First Quarter |
cut as needed |
| Sweet Corn direct sow |
โ | Apr 13 โ May 28 | Apr 23, May 23 First Quarter |
60โ100 |
| Thyme transplant |
Feb 16 | Apr 13 โ May 4 | Apr 23 First Quarter |
cut as needed |
| Zucchini / Summer Squash either |
Mar 23 | Apr 13 โ May 13 | Apr 23 First Quarter |
45โ60 |
| Basil either |
Mar 2 | Apr 20 โ May 13 | Apr 20โ22 Waxing Crescent |
30โ60 |
| Dry Beans direct sow |
โ | Apr 20 โ May 18 | Apr 23 First Quarter |
85โ100 |
| Pole Beans direct sow |
โ | Apr 20 โ May 23 | Apr 23, May 23 First Quarter |
60โ75 |
| Pumpkin direct sow |
Mar 23 | Apr 20 โ May 18 | Apr 23 First Quarter |
90โ120 |
| Rosemary transplant |
Apr 13 | Apr 20 โ May 13 | Apr 23 First Quarter |
cut as needed |
| Tomatillo transplant |
Mar 2 | Apr 20 โ May 13 | Apr 23 First Quarter |
60โ75 |
| Tomato transplant |
Mar 2 | Apr 20 โ May 13 | Apr 23 First Quarter |
60โ85 |
| Winter Squash direct sow |
Mar 23 | Apr 20 โ May 18 | Apr 23 First Quarter |
85โ110 |
| Cantaloupe / Muskmelon either |
Mar 23 | Apr 27 โ May 18 | โ First Quarter |
75โ90 |
| Eggplant transplant |
Feb 16 | Apr 27 โ May 18 | โ First Quarter |
60โ90 |
| Okra direct sow |
Mar 16 | Apr 27 โ May 23 | May 23 First Quarter |
50โ70 |
| Pepper transplant |
Feb 16 | Apr 27 โ May 18 | โ First Quarter |
60โ90 |
| Sweet Potato slips |
โ | Apr 27 โ May 23 | May 2โ7 Waning Gibbous |
90โ150 |
| Watermelon either |
Mar 23 | Apr 27 โ May 18 | โ First Quarter |
70โ90 |
Fall planting in Roswell
Fall dates count backward from the first frost, and they add time back for the โfall factorโ โ days are shortening and cooling, so a crop grows slower than the seed packet promises. Sowing late is the single most common way a fall garden fails.
| Crop | Sow or set out | Best moon days | Days to harvest | Hardiness |
|---|---|---|---|---|
| Tomato | Jun 14 โ Jul 20 | Jun 21 | 60โ85 | very tender |
| Brussels Sprouts | Jun 17 โ Jul 4 | Jun 17โ20 | 90โ110 | hardy |
| Potato | Jun 22 โ Jul 24 | Jun 29 | 70โ120 | semi-hardy |
| Sweet Corn | Jun 27 โ Jul 20 | โ | 60โ100 | tender |
| Pole Beans | Jul 7 โ Jul 20 | โ | 60โ75 | tender |
| Parsley | Jul 10 โ Jul 24 | Jul 15โ20 | 70โ90 | semi-hardy |
| Okra | Jul 12 โ Aug 11 | Jul 21 | 50โ70 | very tender |
| Cabbage | Jul 17 โ Jul 29 | Jul 17โ20 | 65โ90 | hardy |
| Carrot | Jul 17 โ Jul 29 | Jul 29 | 65โ85 | semi-hardy |
| Collards | Jul 17 โ Aug 8 | Jul 17โ20 | 55โ85 | hardy |
| Cucumber | Jul 17 โ Jul 30 | Jul 21 | 50โ70 | tender |
| Broccoli | Jul 22 โ Aug 8 | โ | 55โ80 | hardy |
| Cauliflower | Jul 22 โ Aug 8 | โ | 55โ80 | semi-hardy |
| Green Beans (bush) | Jul 22 โ Jul 30 | โ | 50โ65 | tender |
| Lettuce (head) | Jul 22 โ Aug 3 | โ | 60โ85 | semi-hardy |
| Peas (English/snap) | Jul 22 โ Aug 8 | โ | 55โ75 | hardy |
| Beet | Jul 27 โ Aug 13 | Jul 29 | 50โ65 | semi-hardy |
| Kale | Jul 27 โ Aug 13 | Aug 13 | 50โ65 | hardy |
| Swiss Chard | Jul 27 โ Aug 13 | Aug 13 | 50โ60 | semi-hardy |
| Zucchini / Summer Squash | Jul 27 โ Aug 4 | โ | 45โ60 | tender |
| Basil | Aug 1 โ Aug 19 | Aug 13โ18 | 30โ60 | very tender |
| Kohlrabi | Aug 1 โ Aug 18 | Aug 13โ18 | 45โ60 | hardy |
| Cilantro | Aug 6 โ Aug 18 | Aug 13โ18 | 45โ70 | semi-hardy |
| Lettuce (leaf) | Aug 6 โ Aug 23 | Aug 13โ18 | 40โ55 | semi-hardy |
| Turnip | Aug 6 โ Aug 23 | โ | 40โ60 | hardy |
| Spinach | Aug 11 โ Aug 28 | Aug 13โ18 | 35โ50 | hardy |
| Dill | Aug 16 โ Aug 23 | Aug 16โ18 | 40โ60 | semi-hardy |
| Radish | Aug 16 โ Sep 10 | Aug 28โSep 2 | 22โ35 | hardy |
| Garlic | Sep 30 โ Nov 20 | Sep 30โOct 2, Oct 26โ28 | 240โ300 | hardy |
| Shallot | Oct 14 โ Nov 14 | Oct 26โ31 | 90โ120 | hardy |
Where these numbers come from
The frost dates on this page are observed station normals, not estimates: they come from Roswell Climat (GHCN USC00297605), one of 6,808 U.S. stations in NOAA's 1991โ2020 Climate Normals. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map. Crop timing is expressed as offsets from your frost dates, drawn from university Extension planting guides.
How precise is any of this?
Extension recommendations for the same crop routinely disagree by two to four weeks, and occasionally more, so these offsets should be presented as windows and starting points rather than deadlines. Three things drive the spread. (1) Regional risk tolerance: for warm-season crops, Colorado State and Utah State put tomatoes, peppers and melons out about 14 days after the last frost, while University of Missouri's calendar works out to roughly 25-35 days after the last frost and University of Maryland's window runs from the frost date itself out to 45 days past it. That is a real 6-week spread for the single most popular garden crop, and it exists because a short-season mountain state is optimizing against a short season while a humid continental state is optimizing against cold, wet spring soil. (2) Soil temperature versus calendar date: most Extension services now say the honest trigger is soil temperature at 4 inches, not the frost date, and the frost-relative number is a convenience translation. A cold, wet spring can push the real date two or three weeks past the calendar recommendation. (3) Days-to-maturity is variety-specific and is measured differently for direct-seeded versus transplanted crops - seed catalogs count from transplant date for tomatoes, peppers, eggplant and cole crops, but from sowing for roots and greens - so a 'days to maturity' range of 60-85 for tomato is genuinely 60-85 depending on which packet you bought. Additionally, the average last frost is a 50% probability, meaning half of all years have a frost after that date; Extension services commonly advise waiting 1-2 weeks past it for anything frost-tender, or being prepared to cover. Treat every number here as plus or minus about 10-14 days.
On the station itself: a weather station is one point. Cities hold their heat, valleys pool cold air, and a garden on a north slope can run two weeks behind one a mile away. Treat this page as your starting point and let your own garden correct it โ that is exactly what the journal in the app is for.
Nearby locations
Planting reminders for Roswell
A short note at each new and full moon telling you what is in its window right now for Roswell โ worked out from the frost dates on this page. Free, one click to stop.
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