The four dates that matter
| Date | When | What it means |
|---|---|---|
| Last spring frost (50%) | Mar 7 | Half of all years see a freeze after this date. It is an average, not a guarantee. |
| Last spring frost (10%) | Mar 27 | Only one year in ten freezes after this. Use it for anything you cannot afford to replant. |
| First fall frost (50%) | Nov 27 | Half of all years freeze before this date. Fall crops are counted back from here. |
| First fall frost (10%) | Nov 8 | An early-freeze year. If a crop must finish, aim to harvest before this. |
Spring & summer planting in Charleston
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 | Jan 6 โ Feb 14 | Feb 1 Full Moon |
perennial โ first real harvest next season |
| Garlic cloves/sets Better planted in fall โ see below |
โ | Jan 19 โ Feb 19 | Feb 2โ7 Waning Gibbous |
240โ300 |
| Asparagus (crowns) transplant |
โ | Jan 24 โ Feb 28 | Jan 25, Feb 24 First Quarter |
perennial โ first real harvest 2โ3 years |
| Chives either |
Jan 10 | Jan 24 โ Feb 28 | Jan 24, Feb 18โ22 Waxing Crescent |
75โ90 |
| Onion (from sets/transplants) cloves/sets |
โ | Jan 24 โ Feb 28 | Feb 2โ7 Waning Gibbous |
90โ120 |
| Peas (English/snap) direct sow |
โ | Jan 24 โ Feb 28 | Jan 25, Feb 24 First Quarter |
55โ75 |
| Spinach direct sow |
โ | Jan 24 โ Feb 28 | Jan 24, Feb 18โ22 Waxing Crescent |
35โ50 |
| Cabbage transplant |
Jan 3 | Jan 31 โ Feb 28 | Feb 18โ23 Waxing Crescent |
65โ90 |
| Collards either |
Jan 24 | Jan 31 โ Mar 21 | Feb 18โ23 Waxing Crescent |
55โ85 |
| Kale either |
Jan 24 | Jan 31 โ Mar 7 | Feb 18โ23 Waxing Crescent |
50โ65 |
| Lettuce (leaf) either |
Jan 31 | Jan 31 โ Mar 28 | Feb 18โ23 Waxing Crescent |
40โ55 |
| Potato cloves/sets |
โ | Jan 31 โ Mar 7 | Feb 1, Mar 3 Full Moon |
70โ120 |
| Radish direct sow |
โ | Jan 31 โ Mar 28 | Feb 2โ7 Waning Gibbous |
22โ35 |
| Turnip direct sow |
โ | Jan 31 โ Mar 14 | Feb 2โ7 Waning Gibbous |
40โ60 |
| Broccoli transplant |
Jan 3 | Feb 5 โ Mar 7 | Feb 18โ23 Waxing Crescent |
55โ80 |
| Brussels Sprouts transplant |
Jan 3 | Feb 5 โ Mar 7 | Feb 18โ23 Waxing Crescent |
90โ110 |
| Leek transplant |
Dec 27 | Feb 5 โ Mar 7 | Feb 5โ8, Mar 4โ5 Waning Gibbous |
100โ120 |
| Lettuce (head) transplant |
Jan 17 | Feb 5 โ Mar 7 | Feb 18โ23 Waxing Crescent |
60โ85 |
| Parsley either |
Jan 3 | Feb 5 โ Mar 14 | Feb 18โ23 Waxing Crescent |
70โ90 |
| Parsnip direct sow |
โ | Feb 5 โ Mar 14 | Mar 3 Full Moon |
100โ150 |
| Shallot cloves/sets Better planted in fall โ see below |
โ | Feb 5 โ Mar 7 | Feb 5โ8, Mar 4โ5 Waning Gibbous |
90โ120 |
| Beet direct sow |
โ | Feb 7 โ Mar 28 | Mar 3 Full Moon |
50โ65 |
| Kohlrabi either |
Jan 24 | Feb 7 โ Mar 14 | Feb 18โ23 Waxing Crescent |
45โ60 |
| Carrot direct sow |
โ | Feb 14 โ Mar 28 | Mar 3 Full Moon |
65โ85 |
| Cauliflower transplant |
Jan 3 | Feb 14 โ Mar 7 | Feb 18โ23 Waxing Crescent |
55โ80 |
| Cilantro direct sow |
โ | Feb 14 โ Mar 28 | Feb 18โ23 Waxing Crescent |
45โ70 |
| Swiss Chard direct sow |
โ | Feb 14 โ Apr 6 | Feb 18โ23 Waxing Crescent |
50โ60 |
| Dill direct sow |
โ | Feb 21 โ Apr 6 | Feb 21โ23, Mar 19โ21 Waxing Crescent |
40โ60 |
| Cucumber either |
Feb 14 | Mar 7 โ Apr 6 | Mar 25 First Quarter |
50โ70 |
| Green Beans (bush) direct sow |
โ | Mar 7 โ Apr 21 | Mar 25 First Quarter |
50โ65 |
| Oregano transplant |
Jan 10 | Mar 7 โ Mar 28 | Mar 25 First Quarter |
cut as needed |
| Sage transplant |
Jan 10 | Mar 7 โ Mar 28 | Mar 25 First Quarter |
cut as needed |
| Sweet Corn direct sow |
โ | Mar 7 โ Apr 21 | Mar 25 First Quarter |
60โ100 |
| Thyme transplant |
Jan 10 | Mar 7 โ Mar 28 | Mar 25 First Quarter |
cut as needed |
| Zucchini / Summer Squash either |
Feb 14 | Mar 7 โ Apr 6 | Mar 25 First Quarter |
45โ60 |
| Basil either |
Jan 24 | Mar 14 โ Apr 6 | Mar 19โ24 Waxing Crescent |
30โ60 |
| Dry Beans direct sow |
โ | Mar 14 โ Apr 11 | Mar 25 First Quarter |
85โ100 |
| Pole Beans direct sow |
โ | Mar 14 โ Apr 16 | Mar 25 First Quarter |
60โ75 |
| Pumpkin direct sow |
Feb 14 | Mar 14 โ Apr 11 | Mar 25 First Quarter |
90โ120 |
| Rosemary transplant |
Mar 7 | Mar 14 โ Apr 6 | Mar 25 First Quarter |
cut as needed |
| Tomatillo transplant |
Jan 24 | Mar 14 โ Apr 6 | Mar 25 First Quarter |
60โ75 |
| Tomato transplant |
Jan 24 | Mar 14 โ Apr 6 | Mar 25 First Quarter |
60โ85 |
| Winter Squash direct sow |
Feb 14 | Mar 14 โ Apr 11 | Mar 25 First Quarter |
85โ110 |
| Cantaloupe / Muskmelon either |
Feb 14 | Mar 21 โ Apr 11 | Mar 25 First Quarter |
75โ90 |
| Eggplant transplant |
Jan 10 | Mar 21 โ Apr 11 | Mar 25 First Quarter |
60โ90 |
| Okra direct sow |
Feb 7 | Mar 21 โ Apr 16 | Mar 25 First Quarter |
50โ70 |
| Pepper transplant |
Jan 10 | Mar 21 โ Apr 11 | Mar 25 First Quarter |
60โ90 |
| Sweet Potato slips |
โ | Mar 21 โ Apr 16 | Apr 2โ7 Waning Gibbous |
90โ150 |
| Watermelon either |
Feb 14 | Mar 21 โ Apr 11 | Mar 25 First Quarter |
70โ90 |
Fall planting in Charleston
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 | Jul 12 โ Aug 17 | Jul 21 | 60โ85 | very tender |
| Brussels Sprouts | Jul 15 โ Aug 1 | Jul 15โ20 | 90โ110 | hardy |
| Potato | Jul 20 โ Aug 21 | Jul 29 | 70โ120 | semi-hardy |
| Sweet Corn | Jul 25 โ Aug 17 | โ | 60โ100 | tender |
| Pole Beans | Aug 4 โ Aug 17 | โ | 60โ75 | tender |
| Parsley | Aug 7 โ Aug 21 | Aug 13โ18 | 70โ90 | semi-hardy |
| Okra | Aug 9 โ Sep 8 | Aug 19 | 50โ70 | very tender |
| Cabbage | Aug 14 โ Aug 26 | Aug 14โ18 | 65โ90 | hardy |
| Carrot | Aug 14 โ Aug 26 | โ | 65โ85 | semi-hardy |
| Collards | Aug 14 โ Sep 5 | Aug 14โ18 | 55โ85 | hardy |
| Cucumber | Aug 14 โ Aug 27 | Aug 19 | 50โ70 | tender |
| Broccoli | Aug 19 โ Sep 5 | โ | 55โ80 | hardy |
| Cauliflower | Aug 19 โ Sep 5 | โ | 55โ80 | semi-hardy |
| Green Beans (bush) | Aug 19 โ Aug 27 | Aug 19 | 50โ65 | tender |
| Lettuce (head) | Aug 19 โ Aug 31 | โ | 60โ85 | semi-hardy |
| Peas (English/snap) | Aug 19 โ Sep 5 | Aug 19 | 55โ75 | hardy |
| Beet | Aug 24 โ Sep 10 | Aug 28 | 50โ65 | semi-hardy |
| Kale | Aug 24 โ Sep 10 | โ | 50โ65 | hardy |
| Swiss Chard | Aug 24 โ Sep 10 | โ | 50โ60 | semi-hardy |
| Zucchini / Summer Squash | Aug 24 โ Sep 1 | โ | 45โ60 | tender |
| Basil | Aug 29 โ Sep 16 | Sep 11โ16 | 30โ60 | very tender |
| Kohlrabi | Aug 29 โ Sep 15 | Sep 11โ15 | 45โ60 | hardy |
| Cilantro | Sep 3 โ Sep 15 | Sep 11โ15 | 45โ70 | semi-hardy |
| Lettuce (leaf) | Sep 3 โ Sep 20 | Sep 11โ16 | 40โ55 | semi-hardy |
| Turnip | Sep 3 โ Sep 20 | Sep 3 | 40โ60 | hardy |
| Spinach | Sep 8 โ Sep 25 | Sep 11โ16 | 35โ50 | hardy |
| Dill | Sep 13 โ Sep 20 | Sep 13โ17 | 40โ60 | semi-hardy |
| Radish | Sep 13 โ Oct 8 | Sep 27โOct 2 | 22โ35 | hardy |
| Garlic | Oct 28 โ Dec 18 | Oct 28โ31, Nov 25โ26 | 240โ300 | hardy |
| Shallot | Nov 11 โ Dec 12 | Nov 25โ30 | 90โ120 | hardy |
Where these numbers come from
The frost dates on this page are observed station normals, not estimates: they come from Charleston Intl Ap (GHCN USW00013880), 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 Charleston
A short note at each new and full moon telling you what is in its window right now for Charleston โ worked out from the frost dates on this page. Free, one click to stop.
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