Your spring garden, dated by the soil.

Seeds don’t read calendars

Most planting calendars count forward from your last frost date. The plants don’t. Beans and corn sit in cold ground and rot. Tomatoes set out into it stop and wait, sometimes for weeks. The frost date passed; the soil didn’t warm.

Gardeners who have lost a planting that way usually end up doing the work by hand — a soil thermometer, a notebook, a spreadsheet, waiting for a warm week to hold. This does that work for you, before the season starts.

What it gives you

Tell it where you garden — a town, a dropped pin, or your location if you choose to share it — and what you like to grow. It gives you a dated calendar for the spring: when to start seeds indoors, when to sow, and when to set out.

At launch that means the warm-season garden — tomatoes, peppers, eggplant, squash, cucumbers, melons, beans, okra and corn — and flowers: zinnias, cosmos, marigolds, sunflowers, coneflowers and more.

Cool-season crops are in too, with a wider window. Lettuce, peas and the cabbage family are harder to date than summer crops: in our testing the rule was off by about two weeks on average, so every cool-season date comes as a range that says so. We’d rather show you the uncertainty than hide it.

Why soil, and how we checked

The planner estimates soil temperature four inches down from your local climate record, using a published soil-science method, then finds when each crop’s soil threshold is reliably reached.

We tested it against the planting tables the extension services publish for Alabama, Georgia and Missouri. For summer crops, soil-timed dates came out about twice as close to the extension windows as dates counted from the last frost.

That is agreement with the experts’ own planting windows, at three places. It is not a promise about your weather — a cold spring is still a cold spring.

Every date shows its work

Tap any date and you see why it’s there: the soil temperature that crop needs, the extension service or seed-trial source it came from, and how wide the window is.

Dates come as windows, not single days, because no year is an average year.

What it costs

One garden, free, for as long as you like — a full plan, not a sample.

More gardens, past seasons and export: $4.99 a year. No trial that turns into something else. Cancel in one tap from your iPhone’s subscription settings.

What you need

• An iPhone. Dates work from your own local climate record; the model was tested first against US extension planting tables.
• No account. Your garden stays on your phone.
• Location is optional — you can type a town or drop a pin instead.