Farmer's Planting Calendar
Planting dates come from your frost dates, not the calendar. The last frost spans four months across zones, so "plant in May" is a guess.
Your year, month by month
Every crop, with its dates and its margin
How the zones compare
The same crops against every zone's frost window. Note how little the number of crops that finish changes, and how much the succession count does.
"Plant in May" is a guess about where you live
The average last spring frost spans 120 days — very nearly four months — from zone 3 to zone 10. So the first of May is two weeks before the last frost in zone 3, and more than three months after it in zone 10. A calendar-month instruction is right in the middle of that range and wrong at both ends, which is exactly why it survives: it works for the people who write most of the gardening advice, and neither the too-early reader nor the too-late one can tell from the sentence itself. Every date on this page is computed as an offset from your frost dates instead.
Cold zones can grow almost everything, which is not the usual assumption. Testing nineteen common crops against the frost-free window, eighteen finish in zone 3 — the only casualty is sweet potato, which needs 120 days from a transplant that cannot go out until three weeks after the last frost. What a short season actually costs is margin and repeats. A tomato in zone 3 finishes with 34 days to spare against a great deal more in zone 10, and that slack is the difference between a cool August ending your season and merely slowing it.
Hardiness is why the planting offsets differ so much. Hardy crops — peas, spinach, radish — go in weeks before the last frost and are ruined by heat rather than cold, so a late start wastes their season entirely. Tender crops wait until after it, and the truly tender ones wait weeks longer still, because cold soil stalls them even when nothing freezes. Planting a pepper on the last frost date is not brave; it is just slow. And succession sowing is the change that most improves what a small plot actually yields: sow anything quick in small repeated batches, and the number of rounds that fit is simply the season divided by the days to maturity.
How to use
- Pick your hardiness zone, or better, enter your own frost dates.
- Work from the offsets — hardy crops go in weeks before the last frost.
- Check the margin column before choosing a long-maturing variety.
- Sow anything quick in small repeated batches rather than all at once.
Frequently asked questions
When should I plant my vegetable garden?
That depends on your frost dates rather than on the month, which is why generic advice misleads. Hardy crops like peas, spinach and radish go in several weeks before the last spring frost; half-hardy crops around it; tender crops such as tomatoes and peppers one to three weeks after it. Everything on this page is positioned as an offset from your own dates.
Why is "plant in May" bad advice?
Because the average last spring frost spans 120 days — very nearly four months — from zone 3 to zone 10. The first of May is two weeks before the last frost in zone 3 and more than three months after it in zone 10. The instruction is right in the middle of that range and wrong at both ends, and nothing in the sentence tells the reader which they are.
Can I grow tomatoes in a short season?
Almost certainly. Testing nineteen common crops against the frost-free window, eighteen of them finish even in zone 3 — the only casualty is sweet potato. A short season rules crops out far less often than people assume. What it takes away is margin: a zone 3 tomato finishes with about 34 days to spare rather than months.
What does a longer growing season actually buy?
Margin and repeats, rather than more crops. The extra slack is the difference between a cool spring or a late transplant costing you the harvest and merely delaying it, and a long season fits several more rounds of quick crops. The list of what will grow barely changes; the room for things to go wrong changes enormously.
What is succession sowing?
Sowing a quick crop in small repeated batches instead of all at once, so it matures in a supply rather than a glut. The number of rounds that fit is simply the usable season divided by the days to maturity. It is probably the single change that most improves what a small plot actually yields in food eaten rather than food grown.
Which vegetables can go in before the last frost?
Hardy ones — peas, spinach, radish, lettuce, kale and onions all tolerate frost and several prefer cool weather. They are damaged by heat rather than cold, so starting them late wastes their season entirely. Half-hardy crops such as carrots, beetroot and potatoes go in a week or two before the last frost.
Why do peppers and aubergines wait so long after the last frost?
Because cold soil stalls them even when nothing actually freezes. They want warm ground rather than merely frost-free ground, so putting them out on the last frost date is not brave — it is just slow, and a plant that sulks for three weeks in cold soil is often overtaken by one planted later into warm soil.
Why start seeds indoors?
To buy season that does not exist outdoors. A pepper started eight weeks early is transplanted three weeks after the last frost with two months of growth already done, which is how a 120-day crop fits into a 123-day zone. The cost is that it concentrates the risk into a single transplanting day, which is worth planning around.
How accurate are hardiness zone frost dates?
They are useful averages and nothing more. Frost dates vary enormously within a zone with altitude, slope, proximity to water and how built-up the area is — a garden can sit a fortnight either side of the town it is in, and a low corner of a field frosts when the rest does not. Your own records beat any published figure.
What does days to maturity actually mean?
Days from transplanting for crops that are transplanted, and days from sowing for those that are not — which is a genuine trap when comparing catalogue figures. They also assume good conditions, so a cool summer stretches them. Treat the number as optimistic and prefer a margin over a perfect fit.
What is a hardiness zone?
A band defined by average annual minimum winter temperature, which is what determines whether a perennial survives the winter. It is only loosely related to the length of the growing season, so two places in the same zone can have quite different summers — one more reason to use your own frost dates for annual vegetables rather than the zone alone.
Should I plant earlier to get a longer season?
Usually no. Planting earlier runs into the frost you were avoiding, and cold soil often means an early planting is overtaken by a later one. Choosing shorter-maturing varieties buys margin far more reliably, and starting indoors buys it without the risk — both add season at the end you control rather than the end you do not.
🔒 This tool runs entirely in your browser. Nothing you enter is uploaded, logged, or stored.