When to start seeds indoors: work backward from spring
Turn a last frost date into a realistic indoor sowing schedule, without filling your windowsill too early.
FOR YOUR NEXT GROWING SEASON
Start small.
Grow something
wonderful.
Your free seed starting calculator. Turn a frost date and a few favorite crops into a planting calendar that feels possible.
Plan my growing season Free. No sign-up. Just growing.
A LITTLE HEAD START GOES A LONG WAY
✳
good things are growing ↗Right seed. Right time.A happier start to your garden.
Dates made for your season 32 vegetables, herbs & flowers Keep your calendar, free
A SEASON THAT STARTS WITH YOU
Your garden, right on time.
YOUR GROWING SEASON
Good things take a little timing.
First seeds: Feb 27, 2027
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TomatoStart indoors · 8 seeds / round
SOW INDOORSMar 20, 2027 – Apr 3, 2027
PLANT OUTMay 15, 2027
Growing notes
Wait for warm nights; protect from cold.
Begin hardening off around May 5, 2027.
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PepperStart indoors · 8 seeds / round
SOW INDOORSMar 6, 2027 – Mar 20, 2027
PLANT OUTMay 15, 2027
Growing notes
Slow germination benefits from a warm medium.
Begin hardening off around May 5, 2027.
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BroccoliStart indoors · 8 seeds / round
SOW INDOORSFeb 27, 2027 – Mar 13, 2027
PLANT OUTApr 17, 2027
Growing notes
Harden well before planting into cool weather.
Begin hardening off around Apr 7, 2027.
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LettuceStart indoors · 8 seeds / round
SOW INDOORSMar 6, 2027 – Mar 20, 2027
PLANT OUTApr 10, 2027
Growing notes
Make small repeat sowings; heat can inhibit germination.
Begin hardening off around Mar 31, 2027.
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BasilStart indoors · 8 seeds / round
SOW INDOORSApr 3, 2027 – Apr 17, 2027
PLANT OUTMay 15, 2027
Growing notes
Very frost sensitive; wait for consistently mild nights.
Begin hardening off around May 5, 2027.
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MarigoldStart indoors · 8 seeds / round
SOW INDOORSMar 27, 2027 – Apr 10, 2027
PLANT OUTMay 8, 2027
Growing notes
African types may need an earlier start than dwarf types.
Begin hardening off around Apr 28, 2027.
Dates are based on your frost date and crop timing ranges. Always check your seed packet, soil warmth, and local forecast. How it works
LESS GUESSWORK. MORE GROWING.From seed packet
From seed packet
to something lovely.
01
Start with your frost date
Your local last spring frost date anchors a calendar that makes sense for your garden.
02
Choose your little favorites
Pick vegetables, herbs, and flowers. We’ll work backward to find their sowing windows.
03
Give your season a home
Save your plan, print it for the potting shed, or add planting days to your calendar.
FROM THE JOURNAL
Explore all 60 guides A little know-how goes a long way.
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Build a practical first seed starting setup with trays, mix, lighting, and labels that match the number of plants you need.
Tomato seed starting dates: avoid the oversized transplant
Plan a tomato sowing window, allow for potting up, and choose a plant-out date that respects cool nights.
BEFORE YOU GET GROWING
A few good questions.
Small answers to help you start with confidence.
How does a seed starting calculator work?+
Enter your average last spring frost date and select your crops. We estimate planting dates relative to frost, then count backward by the seedling growing period to find an indoor sowing window. Direct-sown crops receive outdoor sowing windows instead.
Can I use this outside the United States?+
Yes. Enter your own local last spring frost date. Dates and crop estimates are most useful in temperate climates with a spring frost season. Frost-free and tropical climates need local seasonal guidance.
Is a hardiness zone enough to find my frost date?+
No. Hardiness zones describe average extreme winter temperatures. They do not give a precise last frost date. Use local climate records or advice from your local extension service.
What if I already missed the sowing window?+
Choose a faster variety, buy a transplant, or consider a later planting if your season allows it. Starting every crop immediately is not always the best choice.
Is the tool really free?+
Yes. Calendar downloads, quantity estimates, printing, and saving a plan on this device are all free. No account or subscription is required.
Every garden starts somewhere.
Yours can start with a simple plan.
Let’s get growing