LawnWeather

Colorado Lawn Care Calendar

In Colorado, crabgrass preventer typically goes down between Apr 6 and May 20: first in Grand Junction, last in Colorado Springs. Below are typical fertilizer, seeding and frost dates for Denver, Colorado Springs, Fort Collins, Grand Junction, Aurora, Boulder, Greeley and Pueblo, from 2016–2025 weather data. Enter your ZIP code for this year's timing.

When to apply pre-emergent in Colorado

Typically between Apr 6 and May 20, depending on where you live. The window opens first in Grand Junction (around Apr 6) and last in Colorado Springs (around Apr 25). Apply when soil reaches 50°F, before it stays above 55°F.

CityCrabgrass preventer window
Grand JunctionApr 6 – May 1
DenverApr 8 – May 11
PuebloApr 8 – May 4
AuroraApr 13 – May 15
BoulderApr 13 – May 17
Fort CollinsApr 21 – May 19
GreeleyApr 23 – May 17
Colorado SpringsApr 25 – May 20

Cool-season lawn calendar

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

CitySpring fertilizerOverseeding & seedingFall fertilizer
DenverMay 4 – Jun 8Jul 30 – Sep 18Sep 11 – Nov 3
Colorado SpringsMay 13 – Jun 17Jul 29 – Sep 17Aug 13 – Nov 3
Fort CollinsMay 12 – Jun 16Jul 29 – Sep 17Aug 29 – Oct 30
Grand JunctionApr 24 – May 29Aug 11 – Sep 30Sep 15 – Nov 3
AuroraMay 8 – Jun 12Aug 3 – Sep 22Sep 11 – Nov 3
BoulderMay 10 – Jun 14Aug 3 – Sep 22Sep 4 – Nov 5
GreeleyMay 10 – Jun 14Jul 26 – Sep 14Aug 29 – Oct 30
PuebloApr 27 – Jun 1Jul 31 – Sep 19Sep 11 – Nov 7

Frost dates in Colorado

CityLast spring frostFirst fall frost
DenverApr 25Oct 13
Colorado SpringsMay 8Oct 12
Fort CollinsApr 25Oct 12
Grand JunctionApr 21Oct 25
AuroraApr 25Oct 17
BoulderApr 25Oct 17
GreeleyMay 1Oct 9
PuebloApr 24Oct 14

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 Colorado?

Typically between Apr 6 and May 20, depending on where you live. The window opens first in Grand Junction (around Apr 6) and last in Colorado Springs (around Apr 25). Apply when soil reaches 50°F, before it stays above 55°F.

When is the best time to seed grass in Colorado?

Early fall is best for cool-season grass (tall fescue, Kentucky bluegrass, perennial ryegrass): typically from Jul 26 to Sep 30 across Colorado, while soil cools from 65°F toward 50°F.

What type of grass grows in Colorado?

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

Lawn care guides

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