Spring planting forgives. Sow two weeks late in April and you harvest two weeks late in July. Fall planting does not: sow two weeks late in August and frost can take the whole crop the week before it was ready. That is why a fall calendar matters more than a spring one, and why we built the charts below.
Everything here is computed the same way: your zone's typical first fall frost, minus the days to maturity for each crop, minus a 14-day fall factor for slower growth in shortening days, with an extra two-week buffer for frost-tender crops like beans. The prose around the charts shows the math so you can rerun it for your exact street, because your yard has a real frost date and a zone only has an average.
Step 1: Find Your First Frost Date
Your USDA hardiness zone (look it up by zip on the USDA Plant Hardiness Zone Map) tells you winter cold, but for fall planting what you actually need is the average first fall frost. The two correlate well enough for planning:
| Zone | Typical first fall frost | Fall sowing season |
|---|---|---|
| 3 | Sept 1 to 15 | late June to early Aug |
| 4 | Sept 15 to 30 | early July to mid Aug |
| 5 | Oct 1 to 15 | mid July to early Sept |
| 6 | Oct 15 to 31 | late July to mid Sept |
| 7 | Nov 1 to 15 | mid Aug to early Oct |
| 8 | Nov 15 to 30 | late Aug to mid Oct |
| 9 | Dec 1 to 15 | Sept to Nov |
| 10 | frost rare | Oct to Feb, cool season |
Treat the table as a starting point, then tighten it: your local extension office or nearest NOAA weather station publishes the actual average first frost for your area, and a low-lying yard can frost two weeks before the airport five miles away.
Step 2: The Count-Back Math
The formula behind every cell in the big chart:
Last sowing date = first frost date, minus days to maturity, minus 14 days (the fall factor), minus 14 more days if frost kills the crop.
The fall factor is the adjustment extension services recommend because fall crops grow into shortening, cooling days instead of lengthening ones; a 50-day crop sown in August genuinely takes closer to 64.
Worked example, zone 6 with an October 21 frost: Bloomsdale spinach lists 45 days. 45 + 14 = 59 days, so the last sowing lands around August 23. Contender bush beans list 50 days, but beans die at first frost, so 50 + 14 + 14 = 78 days, and the last sowing is around August 4. Same zone, same month, very different deadlines. That is the whole reason this chart exists.
The Chart: Last Direct-Sow Dates by Zone
Dates are the latest sowing that still delivers a full harvest. Earlier is always safer; "early" means the 1st to 10th, "mid" the 11th to 20th, "late" the 21st onward.
| Crop (days) | Zone 3 | Zone 4 | Zone 5 | Zone 6 | Zone 7 | Zone 8 | Zone 9 | Zone 10 |
|---|---|---|---|---|---|---|---|---|
| Radish (22) | early Aug | mid Aug | early Sept | mid Sept | early Oct | mid Oct | early Nov | mid Nov |
| Arugula (40) | mid July | late July | mid Aug | late Aug | mid Sept | late Sept | mid Oct | early Nov |
| Leaf lettuce (45) | mid July | late July | early Aug | late Aug | early Sept | late Sept | early Oct | late Oct |
| Spinach (45) | mid July | late July | early Aug | late Aug | early Sept | late Sept | early Oct | late Oct |
| Mustard greens (45) | mid July | late July | early Aug | late Aug | early Sept | late Sept | early Oct | late Oct |
| Cilantro (50) | early July | mid July | early Aug | mid Aug | early Sept | mid Sept | early Oct | late Oct |
| Turnip (50) | early July | mid July | early Aug | mid Aug | early Sept | mid Sept | early Oct | late Oct |
| Bush bean (50)* | late June | early July | late July | early Aug | late Aug | early Sept | late Sept | early Oct |
| Kale (55) | early July | mid July | late July | mid Aug | late Aug | mid Sept | late Sept | mid Oct |
| Beet (55) | early July | mid July | late July | mid Aug | late Aug | mid Sept | late Sept | mid Oct |
| Swiss chard (55) | early July | mid July | late July | mid Aug | late Aug | mid Sept | late Sept | mid Oct |
| Snap pea (60) | late June | early July | late July | early Aug | late Aug | early Sept | late Sept | mid Oct |
| Carrot (70) | mid June | late June | mid July | late July | mid Aug | late Aug | mid Sept | early Oct |
| Collards (70) | mid June | late June | mid July | late July | mid Aug | late Aug | mid Sept | early Oct |
*Bush beans carry the extra two-week tender-crop buffer; one frost ends them.
Three notes on reading the grid:
- Hardy greens outlive their deadline. Kale, collards, and spinach keep producing well past first frost, so a sowing two weeks after the date in the chart still yields baby greens, just not full-size plants.
- Roots can stay in the ground. Carrots and beets sown by their dates hold in the soil under a thick mulch for weeks after frost, sweetening as they sit.
- Zones 9 and 10 flip the problem. Your constraint is not frost, it is heat. Wait until soil cools in October, then treat October to February as one long cool season. Lettuce and spinach sown into 85 F soil will fail no matter what the calendar allows; our seed germination temperature chart has the thresholds.
Transplant Deadlines: The Cabbage Family
Cabbage and broccoli need more runway than direct sowing allows in most zones, so their chart tracks the last date to set out transplants. Start seeds in trays four to six weeks before these dates; warm summer soil pushes seedlings to transplant size fast.
| Crop | Zone 3 | Zone 4 | Zone 5 | Zone 6 | Zone 7 | Zone 8 | Zone 9 | Zone 10 |
|---|---|---|---|---|---|---|---|---|
| Cabbage (last transplant) | early July | mid July | early Aug | mid Aug | early Sept | mid Sept | early Oct | late Oct |
| Broccoli (last transplant) | late June | mid July | late July | mid Aug | late Aug | mid Sept | late Sept | mid Oct |
Both finish maturing through light frosts without damage, and cabbage flavor improves for it. Our 7-variety heirloom cabbage pack mixes early 60-to-70-day types with longer storage types; in zones 6 and colder, count on the early types for fall.
Crop Key: The Numbers Behind the Chart
Days to maturity below are the figures we used, taken from the specific varieties we grow. If you sow a different variety, rerun the math with its packet number.
| Crop | Days used | Frost tolerance | Our variety |
|---|---|---|---|
| Radish | 22 | light frost | Cherry Belle |
| Arugula | 40 (baby 21) | light frost | Heirloom arugula |
| Leaf lettuce | 45 | light frost, upper 20s F | 20-variety lettuce pack |
| Spinach | 45 | hardy to the teens F | Bloomsdale |
| Mustard greens | 45 | light frost | |
| Cilantro | 50 | light frost | Santo slow-bolt |
| Turnip | 50 | hard frost | |
| Bush bean | 50 | none, killed at 32 F | Contender |
| Kale | 55 (baby 30) | hardy to about 20 F | 4-variety kale pack |
| Beet | 58 | light frost, roots hold under mulch | Detroit Dark Red |
| Swiss chard | 55 | light frost, mid 20s F | |
| Snap pea | 60 to 70 | plants take light frost, pods do not | Cascadia |
| Carrot | 70 | tops take frost, roots hold under mulch | Rainbow carrot pack |
| Collards | 70 | hardiest of all, near 20 F and below | Vates |
| Cabbage | 60 to 70 from transplant | hard frost improves flavor | 7-variety pack |
Buying Time at the Margins
Two adjustments stretch every date in the chart:
- Row cover. A lightweight floating row cover buys 2 to 4 degrees F of frost protection, and heavyweight fabric buys 4 to 8. In practice that converts your first light frosts from an ending into a speed bump and adds two to four weeks to the season. Our beginner fall garden guide covers the setup.
- Sow in waves, not all at once. A single sowing on the last safe date is a bet on average weather. Sowing every week to ten days up to that date is a portfolio; whichever wave hits the best window wins. That is succession planting, and fall is its best season.
If you would rather not assemble the roster crop by crop, our Fall Vegetable Seed Pack bundles 12 cool-weather varieties matched to the chart above. And if frost has already closed your window for the crops above, the season is still not over; see what to plant in November for garlic and the overwinter crowd. And for the month-by-month version of this chart with variety-level detail, start with what to plant in July and August for a fall harvest.
Sources: USDA Plant Hardiness Zone Map (frost planning by zone); University of Arkansas Cooperative Extension, Planting Dates for Fall Vegetable Production; University of Minnesota Extension on midsummer planting and the fall growth adjustment. Frost windows are climatological averages; verify your local date with your county extension office.
