Sowing planner

Everything below is worked backwards from the day seedlings can go outside.

The sowing planner is free for everyone for now, with no account needed.

How to use a plan

Give your last spring frost (a zip code finds it) and add the plants you want to grow.
Each plant gets a table of dated steps. Start is the day to begin that step; the steps run one after another until Plant out, which is your last frost.
A plant with more than one protocol shows each one. They are alternatives from different experiments. Pick one; where the source gave a result, the line under its table says how well it did.
Click a step’s name to see how it is done: moist stratification in a paper towel, light, GA-3 and the rest, in Deno’s own words. The whole guide, including growing the seedlings on, is How the steps are done.
Add to calendar downloads the steps as events for your calendar app.

Your last spring frost

A zip code, or a date if you already know it (what a last frost date is). The lookup is a static file — nothing is sent anywhere and no service is called.

Zip code

Last frost date

Showing the national default of May 3, which is wrong for most places.

32,883 zip codes, from NOAA's 1991–2020 climate normals matched to the nearest weather station. A station can sit a long way below you: the one used, and how far away it is, are named when you look a zip up. A zip that is not on the list (a PO box, say) uses the closest one that is.

Species

Search for a plant and add it. Add as many as you like — each plant’s protocols appear together, the plant to start first at the top.

Results appear as you type. Arrow keys to move, Enter to add, Escape to clear.

Sowing planner

Paid account required

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