Seattle lawn care, month by month
| Month | Tasks |
|---|---|
| January | Dormant — keep leaves cleared, stay off frozen turf |
| February | Apply crabgrass pre-emergent |
| March | Apply crabgrass pre-emergent · Light feeding after green-up |
| April | Light feeding after green-up |
| May | Mow high (3–3.5″); water deeply in dry spells; no feeding in heat |
| June | Mow high (3–3.5″); water deeply in dry spells; no feeding in heat |
| July | Mow high (3–3.5″); water deeply in dry spells; no feeding in heat |
| August | Mow high (3–3.5″); water deeply in dry spells; no feeding in heat |
| September | Aerate + overseed · Main fall feeding |
| October | Aerate + overseed · Main fall feeding · Winterizer feeding |
| November | Winterizer feeding · Final mow of the year |
| December | Final mow of the year |
Reading the Seattle lawn year
Seattle runs on the classic northern rhythm: a short, important spring (pre-emergent before soil hits 55°F, one light feeding), a defensive summer (mow tall, water deep, feed nothing), and then the season that actually builds a lawn — early fall, when aeration, overseeding around Sep 18 – Oct 3, and the year's main feeding all land before the Nov 17 frost closes the year.
Grasses that fit Seattle
Frequently asked questions
When should I overseed my lawn in Seattle?
For cool-season grass (bluegrass, fescue, ryegrass), overseed in early fall — in Seattle that means roughly Sep 18 – Oct 3, timed 45–60 days before the average first fall frost (Nov 17) so seedlings establish before cold. Spring works as a backup but collides with crabgrass season.
When do I put down crabgrass preventer in Seattle?
Aim for Feb 20 – Mar 13 — the estimated stretch when Seattle soil approaches the ~55°F germination threshold, anchored to the average last frost (Mar 13). It's an estimate: a soil thermometer reading 50–55°F at 2″ depth for several days is the precise trigger, and pre-emergent must go down before crabgrass sprouts, not after.
When should I stop mowing in Seattle?
Keep mowing as long as the grass grows — in Seattle that's typically until Nov 10 – Dec 1, around the average first fall frost (Nov 17). Take the final cut slightly shorter to discourage snow mold.
What grass grows best in Seattle?
Washington is cool-season country: Kentucky bluegrass, tall fescue, perennial ryegrass, fine fescue. See the grass guides linked below for identification and care.