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USDA Zones, Frost Dates & Calendar FoundationsCount-Forward Method: Direct Sowing After Last Frost
Counting backward works for transplants. For seed that goes straight into the ground, you count forward from the last frost and let the soil have a say.
Key points
- Sow hardy crops before the frost date and tender crops after it.
- Choose a frost probability that fits your risk tolerance.
- Confirm every count with soil temperature and a forecast.
- Wait in a cold, wet spring, since a late stand beats a rotted one.
What is the count-forward method?
The count-forward method sets a sowing date by adding or subtracting a number of weeks from your last spring frost date. Hardy crops are sown before the frost date, and tender crops are sown after it. The result is a target, which you then confirm with a soil thermometer and the forecast.
It suits crops that dislike root disturbance or grow fast enough that transplanting is not worth the trouble, such as carrots, beets, radishes, beans and corn.
For example, if you sow carrots a few weeks before your anchor date, expect slow emergence in cool soil. That is normal, so keep the bed moist and avoid giving up on it too soon.
Which crops go before and after the frost date?
Crops that tolerate cold can be sown while the soil is still cool, as soon as it can be worked and is not waterlogged. Those that cannot take frost wait until the risk has passed. Between the two groups sits a middle band of crops that tolerate a light frost but not a hard freeze.
One Wisconsin chart lists minimum soil temperatures around 45 degrees Fahrenheit for crops like lettuce, beets and carrots, and much warmer minimums for beans, squash and tomatoes. The chart gives you the sort order, even if you adjust the numbers for your local guidance.
- Hardy: sow before the last frost, when soil is workable.
- Half-hardy: sow around the frost date.
- Tender: sow after the frost date, in warm soil.
How do you choose the frost date for the count?
Pick a frost probability level for your spring anchor. NC State Extension explains how risk-averse growers use the later, 10 percent date, moderate growers use the 50 percent date and risk-tolerant growers use the earlier, 90 percent date. Your choice sets the starting point of the count.
Choose the date at the temperature threshold that fits the crop. A tender crop might use the frost threshold at 36 degrees Fahrenheit, while a crop that tolerates cold could use a lower one.
How do you run the count and confirm it?
Take the anchor date, add or subtract the weeks you want, and write the target in your calendar. A few days before the date, check the forecast for lows and measure soil temperature at seed depth on several mornings in a row.
For example, if your anchor falls in early May and you want to sow bush beans two weeks later, you aim for mid May. If the soil is still below the bean minimum on that date, wait a few days and test again. Beans sown in cold, wet soil are prone to rot.
Mark the date you actually sowed and the date seedlings emerged. The gap between them tells you how well your soil reading matched the crop's needs.
What if spring runs cold or wet?
Delay. Seeds that sit in cold soil for weeks rot or emerge weakly, and a thin stand is worse than a late one. Alberta agriculture guidance notes that early seeding often fails to give a head start for this reason.
Warm the soil with clear or dark plastic ahead of time, or use raised beds. Be ready with row cover for any frost that shows up after emergence.
How do you use succession and thinning?
For quick crops, repeat the count at regular intervals, and mark each new sowing on the calendar. Thin seedlings to the spacing on the packet as soon as they are large enough, since crowding slows growth and invites disease.
Keep records of each sowing date, the soil reading and the result. A sheet of notes will tell you quickly whether your counts were too early, too late or about right.
Fast crops such as radishes and bush beans respond well to a repeated count, with a new sowing every week or two for a stretch. Slower crops such as corn are better planted in a few blocks.
What mistakes should you avoid?
Sowing everything at once is one. Using the frost date without checking soil is another. A third is sowing too deep for small seed, which keeps it from emerging, so follow the depth on the packet.
Remember also that wet soil in early spring can crust or pack when you work it. Wait until a handful crumbles rather than forming a ball.
Keep seed packets in a dry, cool place, and note the packed-for year. Old seed may need a heavier sowing or a germination test, which you can do on a damp paper towel before the season.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.