Seed starting calculator

Enter your average last spring frost date. You'll get a schedule of when to start each crop indoors and when to move it outside.

Average last frost date

Don't know it? Search "last frost date" with your ZIP code, or ask your local extension office.

–first seeds to start

Last frost date: –

Start onions first. Most other crops start a few weeks later.

Your schedule

Crop	Start indoors	Move outside

How the schedule works

Each crop has a typical number of weeks it needs indoors before it's big enough to transplant. Cold-hardy crops like broccoli and kale can go outside a couple of weeks before the last frost. Heat lovers like tomatoes and peppers wait until a week or two after it, once nights stay warm.

Seed packets list their own timing, and they're the best guide for a specific variety.

Common questions

What does "last frost date" mean?

It's the average date of the last light freeze in spring for your area. It's an average, so a later frost is still possible. Keep an eye on the forecast before moving tender plants out.

What is hardening off?

Seedlings raised indoors need about a week of gradual exposure to sun and wind before transplanting. Start with an hour or two outside in a sheltered spot and increase the time each day.

Which crops shouldn't be started indoors?

Root crops like carrots, radishes and beets, and large-seeded crops like beans, peas and corn, usually do best sown directly in the garden.