Your garden app says 70 days until frost. It has never asked what you planted.

The October problem

You planted something in the summer. It grew beautifully. It set fruit. And then one night in October it went black, with everything still green on it.

Everyone who gardens has done this at least once, and the annoying part is that it was knowable in July. Not guessable — knowable, from two numbers that already existed, that you already had access to, and that nobody ever puts side by side.

The two numbers, and why nobody multiplies them

The first number is on the app. Ours prints it plainly: 112 days into the season. 70 days until your first frost. It is a good sentence. It is easy to compute, because it depends only on where you live.

The second number is on the seed packet. 70 days. 85 days. Also true, also easy.

Put them together and you have the only question that matters in August: does the thing in my bed have time? And almost nothing puts them together, because the two numbers live in different places — one belongs to your garden, one belongs to your plant, and no screen owns both.

What our own records say, for 967 varieties

So we did the multiplication. We took every crop in our database that frost kills — not the hardy ones, not the cover crops sown deliberately to overwinter — and checked each variety's days to maturity against 70 days.

967 varieties across 32 crops. 444 finish comfortably. 486 cannot finish at all. 37 land on a knife edge, where you get a harvest only if your variety runs to the fast end of its range.

Roughly half. And the split is not spread evenly — it is nearly total in both directions:

• Winter squash: 0 of 55 varieties make it. Not one. They run 75 to 112 days, and the fastest of them is still five days past the deadline.
• Pumpkins: 1 of 44.
• Watermelon: 5 of 47. Melon: 6 of 49. Sweet corn: 10 of 48.
• Cucumbers: 54 of 54. Summer squash: 50 of 50. Okra: 20 of 20. Every one.

That is the whole argument. Two gardeners with the same 70 days, the same soil and the same weather get opposite outcomes, decided entirely by which packet they picked up in May. And the countdown on the screen says the same thing to both of them.

The crop name is not enough, and our own crop page proves it

Here is the part that surprised us. Knowing you planted "peppers" does not answer the question either.

Our pepper record holds 55 varieties with 20 different maturity figures, running from 58 days to 120. Against a 70-day clock: 10 are safe, 8 are a gamble, 37 will not make it.

And our own crop-level summary for peppers says "70–85 days" — a range that is wrong at both ends. Real peppers in our own database run twelve days faster than that and thirty-five days slower. The tidy number on the crop page hides the only variation that decides your season.

Tomatoes are the same shape: 115 varieties, 47 safe and 67 out of time. "I planted tomatoes" is not an answer. "I planted Brandywine" is.

And winter squash makes the point twice over. Its crop-level entry says 60–100 days. Its 55 varieties actually run 75 to 112 — so the summary is optimistic by fifteen days at the fast end, and the crop it describes has no variety that can do what the summary claims. We found that while writing this piece, in our own data, because a check told us a number in the summary was not in the page.

What we hold, what we don't, and the part where we are the problem

Our app has the frost date. Our app has the maturity figures. The function that draws the countdown does not take a crop at all. It accepts today's date, your last frost and your first frost, and that is the entire input. It cannot warn you about your peppers because it has never been told you have any.

Nothing is broken. No error, no wrong number — both screens are correct. They have simply never been introduced, which is exactly how a gardener ends up finding out in October.

This is not built yet, and we are not going to describe it as though it were. What we have is the data underneath it, published free, so you can do the multiplication yourself today.

What to do about it this week

Look up the variety, not the crop. The packet has the name on it. The difference between two peppers in our own database is sixty-two days, which is most of a season.

Count backwards from your first frost, not forwards from today. Frost date minus maturity days is your real deadline, and it has usually passed before it feels like it has.

If it cannot finish, change what you are asking for. A winter squash that will not ripen is still summer squash if you pick it small. Green tomatoes ripen indoors. A crop that misses its window is not always a loss — it is often a different harvest, decided in August rather than discovered in October.

Where these numbers are soft, and one thing we found wrong on the way

70 days is our app's default frost date, not yours. It assumes a first frost of 21 October, counted from mid-August. Your own date may be weeks either side, and the whole point of this piece is that the number should be yours — look yours up.

Days to maturity is measured from two different starting lines and we have written about that before. Across these tender varieties, 580 figures are counted from sowing and 470 from setting out a transplant. Peppers, tomatoes, melons and eggplant are transplant-counted — so for those, "70 days" starts when the plant goes in the ground, not when the seed does. We have not adjusted between the two here, and a strict version of this analysis would. The two starting lines, in full.

And we found a real fault in our own data while doing this. Three crops — chayote, cosmos and garden petunia — list dozens of varieties that all carry the same maturity figure, which is the crop-level number copied down rather than anything measured about those varieties. We excluded them from every count above. It looked like variety data and it was not, and the only reason we caught it was checking how many distinct values each crop actually held.