LawnWeather

Idaho Lawn Care Calendar

In Idaho, crabgrass preventer typically goes down between Apr 5 and Jun 6: first in Meridian, last in Idaho Falls. Below are typical fertilizer, seeding and frost dates for Boise, Idaho Falls, Coeur d'Alene, Meridian and Pocatello, from 2016–2025 weather data. Enter your ZIP code for this year's timing.

When to apply pre-emergent in Idaho

Typically between Apr 5 and Jun 6, depending on where you live. The window opens first in Meridian (around Apr 5) and last in Idaho Falls (around May 3). Apply when soil reaches 50°F, before it stays above 55°F.

CityCrabgrass preventer window
MeridianApr 5 – May 7
BoiseApr 10 – May 8
Coeur d'AleneApr 27 – May 18
PocatelloApr 29 – May 22
Idaho FallsMay 3 – Jun 6

Cool-season lawn calendar

Lawns across Idaho are mostly cool-season grass (tall fescue, Kentucky bluegrass, perennial ryegrass).

CitySpring fertilizerOverseeding & seedingFall fertilizer
BoiseMay 1 – Jun 5Aug 3 – Sep 22Sep 10 – Nov 2
Idaho FallsMay 30 – Jul 4Jul 20 – Sep 8Aug 2 – Oct 21
Coeur d'AleneMay 11 – Jun 15Aug 7 – Sep 26Aug 17 – Oct 31
MeridianApr 30 – Jun 4Aug 6 – Sep 25Sep 10 – Nov 5
PocatelloMay 15 – Jun 19Jul 22 – Sep 10Aug 17 – Oct 23

Frost dates in Idaho

CityLast spring frostFirst fall frost
BoiseApr 20Oct 17
Idaho FallsMay 11Oct 3
Coeur d'AleneApr 23Oct 21
MeridianApr 19Oct 20
PocatelloMay 13Oct 5

Median dates, 2016–2025. A dash means frost does not occur in most years.

Frequently asked questions

When should I put down pre-emergent in Idaho?

Typically between Apr 5 and Jun 6, depending on where you live. The window opens first in Meridian (around Apr 5) and last in Idaho Falls (around May 3). Apply when soil reaches 50°F, before it stays above 55°F.

When is the best time to seed grass in Idaho?

Early fall is best for cool-season grass (tall fescue, Kentucky bluegrass, perennial ryegrass): typically from Jul 20 to Sep 26 across Idaho, while soil cools from 65°F toward 50°F.

What type of grass grows in Idaho?

Most lawns in Idaho are cool-season grass (tall fescue, Kentucky bluegrass, perennial ryegrass).

Lawn care guides

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