1 Your location

The safer date moves every sowing date later. Pick it if late frosts often catch you out, or if you'd rather plant a little late than lose seedlings.

2 Your seed-starting dates

Example: Plano, TX (75024). Search above for your own place.

Start the first seeds
Nov 29
Onions, the year before your last frost
Tomatoes indoors
Jan 17 – Feb 7
out Mar 14 – Mar 21
Average last frost
Mar 7
half of years end later

Counted back from the average last frost for Plano, TX (75024) (NOAA station Richardson, 6.5 mi away).

CropSow indoorsWeeks indoorsStart hardening offPlant outside
Onions (from seed)Nov 29 (the year before) – Dec 13 (the year before)8–10Jan 24Feb 7
CabbageDec 27 (the year before) – Jan 104–6Jan 24Feb 7
KaleDec 27 (the year before) – Jan 104–6Jan 24Feb 7
BroccoliDec 27 (the year before) – Jan 244–6Jan 24Feb 7 – Feb 21
LettuceJan 3 – Jan 174–5Jan 24Feb 7 – Feb 14
CauliflowerJan 10 – Jan 244–6Feb 7Feb 21
PeppersJan 10 – Jan 248–10Mar 7Mar 21
EggplantJan 10 – Jan 318–10Mar 7Mar 21 – Mar 28
TomatoesJan 17 – Feb 76–8Feb 28Mar 14 – Mar 21
BasilJan 24 – Feb 76–8Mar 7Mar 21
CucumbersFeb 14 – Feb 283–4Feb 28Mar 14 – Mar 21
Squash and zucchiniFeb 21 – Feb 283–4Mar 7Mar 21
Pumpkins and winter squashFeb 21 – Feb 283–4Mar 7Mar 21
MelonsFeb 21 – Feb 283–4Mar 7Mar 21

Indoor weeks and planting-out times from UNH Cooperative Extension; hardening off starts two weeks before planting out (University of Minnesota Extension). Cool crops go out before the last frost; warm crops after it. If late frosts are common where you are, plant warm crops after Mar 29, the 1-in-10 date.

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