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Garden Planning, Succession & Crop RotationDirect Sow Calendar by Crop
A direct sow calendar tells you which crops go into the ground as seed and in what order. The most reliable one is built from your own frost dates and soil temperature, not from a date printed on a chart.
Key points
- Build the calendar from your own last and first frost dates, not a generic chart.
- Sort crops by cool-soil and warm-soil tolerance, then check each crop's minimum soil temperature in a local extension guide.
- Read soil temperature at seed depth over several mornings before you sow.
- Space out quick crops and count back from fall frost for the last sowing.
- Record results so next year's calendar is more accurate.
What is a direct sow calendar?
A direct sow calendar is a dated list of the crops you will seed straight into the garden bed instead of starting indoors. It orders those crops by how much cold, heat and moisture each one tolerates at germination.
Printed calendars are written for an average place. Your garden may be colder, warmer, wetter or more sheltered than that average, so treat any generic chart as a rough draft and correct it with local facts.
How do you build one from your last frost date?
Start with the average last spring frost date for your location. Your state extension office or the National Weather Service can point you to local frost records. Remember that a plant hardiness zone describes average winter minimum temperature. It does not give a frost date or a planting date.
Next, read the seed packet or your extension planting guide for each crop. Most give an offset such as sowing some weeks before or after the last frost. For example, if your last frost usually falls around the middle of May and a crop is sown two weeks before that date, your target is around the beginning of May. That is only an example, so use your own date and your own crop guidance.
- Write the frost date at the top of the page.
- Add each crop's offset from the packet or an extension guide.
- Convert the offsets into target weeks, then adjust for the weather that year.
Which crops go in cool soil and which need warm soil?
Sort crops into two groups. Cool-season crops such as peas, spinach, radishes, lettuce and carrots germinate in cool soil and can be seeded early, though germination is slow when the ground is cold and soggy. Warm-season crops such as beans, corn, squash and cucumbers rot or stall in cold soil and should wait until the ground has warmed and frost danger has passed.
Within each group, timing still varies. Check your state extension planting guide for the minimum soil temperature each crop needs, because the numbers differ by crop and are best read from a local source.
How do you check soil temperature before sowing?
Push a soil thermometer to seed depth in the morning, when the ground is at its coolest, and repeat for several days. One warm afternoon does not mean the bed is ready. A steady trend matters more than a single reading.
Raised beds and dark, well-drained soil warm sooner than heavy, wet ground. If you garden in several spots, take readings in each, since a south-facing bed and a shaded corner can differ by weeks.
How do you plan successive sowings?
Quick crops such as radishes, lettuce and bush beans can be sown again every couple of weeks so the harvest does not arrive all at once. Longer crops are usually sown once or twice.
Count backward from your first fall frost as well. Take the days to maturity on the packet, add a margin because growth slows as days shorten, and you will see the last sensible sowing date for a fall crop.
How do you adjust the calendar for cold snaps and wet springs?
A calendar is a plan, and the weather will test it. If a cold, wet stretch arrives after you sow, small seeds can rot in the ground or the seedlings can stall. Wait a few days for the soil to drain and warm before reseeding, and check whether anything has come up before you assume it failed.
Keep a little seed back for repairs. Many gardeners hold some seed in reserve for gaps, and how much you need depends on the crop and the season, so use your own records to decide.
Row cover and similar protection can help a little with chill and with wind, though it does not replace waiting for soil to warm. Ask your county extension office what local gardeners use.
What mistakes ruin a direct sow plan?
The common ones are sowing by the calendar date alone, sowing into saturated soil, burying small seed too deep and forgetting to keep the seedbed evenly moist until the seedlings emerge. A crust that forms on the surface after rain can also block seedlings.
Keep notes each year on what you sowed, when, and how well it came up. After two or three seasons your own records will beat any printed chart.
Spacing matters as well. Sowing far too thickly makes thinning a chore and can invite disease in crowded seedlings, so follow the depth and spacing on the packet.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.