Guides · 6 min read
How to count indoor start dates
Weeks before last frost, not a national calendar. Peppers first. Beans never.
Find last frost, then subtract
Match your ZIP. Note the typical last spring frost. Peppers go in eight weeks before that date, tomatoes six, basil and lettuce three to four, squash two to three. Onions can start ten weeks out if you want big bulbs.
The Start dates page does this arithmetic for every crop we cover. A national 'start tomatoes on March 15' article is written for someone else's frost.
The room is part of the date
A cold spare bedroom adds a week. A heat mat subtracts one for nightshades. If you do not have a light two inches above the leaves, wait and direct-sow what you can rather than grow a tray of thread.
Do not start these indoors
Carrots, radish, beets, beans, peas, dill, and potatoes. They stall or fork or sulk when transplanted. Direct-sow them on the outdoor date, not the indoor one.
Match your ZIP · Shop a kit · Start dates
The sow list
A note when it is time to sow
Seasonal, not daily. We will send what to start in your zone, and skip the rest of the year.
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A first garden that actually finishes
Six crops, one 4×8 bed, and the mistakes that waste a spring.
Seeds for containers, balconies, and rented light
Renters now out-buy homeowners on vegetable and herb seed. The packets have to match the pot.
Short-season Midwest: Chicago and zone 5–6
Last frost in mid-April. First frost in mid-October. That is the whole argument.