When to plant basil in Idaho

Plant out in Boise City

May 1–May 15

Across Idaho the window opens between April 13 and May 19. Find your city below; the dates follow each town's own average last frost.

Start indoors, Boise City: Mar 13–Mar 27
Plant out, Boise City: May 1–May 15
Sow outdoors, Boise City: May 1–May 15
Last sowing for a harvest: Jul 24
Last frost, Boise City: Apr 24

Start seeds indoors 4–6 weeks before the last frost; plant out 1–3 weeks after the last frost; sow outdoors 1–3 weeks after the last frost. Basil blackens below 50°F. Wait a week or two after the last frost.

Basil planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

JanFebMarAprMayJunJulAugSepOctNovDec

Boise CityMay 1–May 15

MeridianMay 1–May 15

NampaMay 6–May 20

CaldwellMay 6–May 20

Idaho FallsMay 16–May 30

PocatelloMay 9–May 23

Coeur d'AleneApr 29–May 13

Twin FallsMay 7–May 21

Post FallsApr 29–May 13

RexburgMay 19–Jun 2

LewistonApr 13–Apr 27

EagleMay 6–May 20

KunaMay 1–May 15

StarMay 6–May 20

AmmonMay 16–May 30

Questions

When should I plant basil in Idaho?

In Boise City, plant out from May 1 to May 15. Across Idaho the window opens between April 13 and May 19, depending on the local last frost.

How is this date worked out?

Start seeds indoors 4–6 weeks before the last frost; plant out 1–3 weeks after the last frost; sow outdoors 1–3 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Idaho

Basil in other states

Frost dates for every city in Idaho