Planting decision
What can I still plant?
Enter a ZIP code. This counts the growing days left before your first fall freeze, adds the frost tolerance each crop actually has, and tells you — crop by crop — whether there is still time.
How this decides
Every vegetable needs a set number of days to maturity — 28 for a radish, 55 for a bush bean, 100 for a pumpkin. The tool counts the days from today to your first fall freeze, then adds a grace window for crops that survive one: nothing for tender crops like beans and squash, about two weeks for light-frost crops, about three and a half for hardy ones. Kale, spinach, collards and carrots are genuinely better after a frost, not merely tolerant of it.
Compare that total against the crop's days to maturity and the answer falls out. Room to spare is a yes. A few days short is sow today, fastest variety on the rack. Far short is next spring — except for leafy greens, which never had to finish anyway and can be cut as baby leaves.
Heat, the other half
A frost date says nothing about summer. Where the average daily high in June–August is at or above 90 °F — Austin is 96, Phoenix 105 — heat rather than frost is what decides whether a sowing works, and the tool splits the crops accordingly from May through September.
Above roughly that mark tomato and pepper pollen stops being viable, beans drop their blossoms and sweet corn pollinates badly, so those crops keep growing but set a thin crop until nights cool. Cool-season greens and brassicas do worse: they run to seed instead of heading, which is why the tool holds them rather than calling them sowable. Okra, southern peas and sweet potato are the ones that genuinely want the weather.
Which crop falls in which group is a judgement, drawn from conventional extension guidance, and it varies by variety. It is not in the same tier as the freeze dates, which are measured and cited per station. The summer temperature itself is measured — it is NOAA's published June–August mean daily maximum for the same station named above.
Where the numbers come from
Freeze dates are NOAA 1991–2020 Climate Normals, read from the nearest station to your ZIP code's centroid. Every result names that station and how far away it is, because a station 30 km out on the plains is a different microclimate from your yard and you should be able to judge that for yourself. Hardiness zones are the USDA 2023 Plant Hardiness Zone Map.
NOAA publishes freeze dates as a probability distribution, not an average — there is no mean in the source data. The median is the default here; the safe option uses the early tail, which the first freeze beats in roughly one year out of ten.
Days-to-maturity figures are conventional seed-catalogue numbers and vary by variety. They are the soft half of this calculation. The freeze dates are the measured half.