LawnWeather

Washington Lawn Care Calendar

In Washington, crabgrass preventer typically goes down between Mar 31 and May 15: first in Kennewick, last in Spokane. Below are typical fertilizer, seeding and frost dates for Seattle, Spokane, Tacoma, Yakima, Vancouver, Bellevue, Kennewick and Bellingham, from 2016–2025 weather data. Enter your ZIP code for this year's timing.

When to apply pre-emergent in Washington

Typically between Mar 31 and May 15, depending on where you live. The window opens first in Kennewick (around Mar 31) and last in Spokane (around Apr 26). Apply when soil reaches 50°F, before it stays above 55°F.

CityCrabgrass preventer window
KennewickMar 31 – May 3
VancouverApr 4 – May 9
SeattleApr 5 – May 14
BellevueApr 5 – May 14
TacomaApr 17 – May 16
BellinghamApr 17 – May 20
YakimaApr 18 – May 6
SpokaneApr 26 – May 15

Cool-season lawn calendar

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

CitySpring fertilizerOverseeding & seedingFall fertilizer
SeattleMay 7 – Jun 11Sep 1 – Oct 21Jul 16 – Nov 13
SpokaneMay 8 – Jun 12Jul 31 – Sep 19Aug 21 – Oct 31
TacomaMay 9 – Jun 13Aug 27 – Oct 16Jul 16 – Nov 10
YakimaApr 29 – Jun 3Jul 31 – Sep 19Aug 24 – Nov 1
VancouverMay 2 – Jun 6Sep 9 – Oct 29Jul 17 – Nov 24
BellevueMay 7 – Jun 11Aug 26 – Oct 15Jul 16 – Nov 13
KennewickApr 26 – May 31Aug 22 – Oct 11Sep 11 – Nov 10
BellinghamMay 13 – Jun 17Aug 23 – Oct 12Jul 15 – Nov 10

Frost dates in Washington

CityLast spring frostFirst fall frost
SeattleMar 12Nov 15
SpokaneApr 23Oct 14
TacomaMar 21Nov 10
YakimaApr 21Oct 14
VancouverMar 19Nov 23
BellevueMar 12Nov 9
KennewickMar 21Nov 5
BellinghamMar 11Nov 6

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 Washington?

Typically between Mar 31 and May 15, depending on where you live. The window opens first in Kennewick (around Mar 31) and last in Spokane (around Apr 26). Apply when soil reaches 50°F, before it stays above 55°F.

When is the best time to seed grass in Washington?

Early fall is best for cool-season grass (tall fescue, Kentucky bluegrass, perennial ryegrass): typically from Jul 31 to Oct 29 across Washington, while soil cools from 65°F toward 50°F.

What type of grass grows in Washington?

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

Lawn care guides

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