Pacific Northwest Lawn Mowing Guide
The Pacific Northwest’s mild, wet climate keeps grass growing most of the year, and feeds moss just as well. The questions here aren’t about beating heat; they’re “can I mow a wet lawn?” (yes, with a sharp blade and a raised deck) and “how do I beat moss?” (mow higher, keep the lawn fed, and fix the shade and drainage: moss killer alone just resets the clock).
What grass do you have?
- Perennial ryegrass: fast to establish in cool soil; the usual choice west of the Cascades.
- Fine fescue: shade and low-input lawns; pairs well with ryegrass.
Mowing heights for Northwest grasses
| Grass | Mowing height | Notes |
|---|---|---|
| Perennial ryegrass | Western Oregon 2–3 in; western Washington 1.25–1.5 in; east of the Cascades 1.5–2.5 in; Idaho 1–2 in | Sharp blade matters: ryegrass shreds at low blade quality |
| Fine fescue | Western Oregon 2–3 in; western Washington 1.25–1.5 in; east of the Cascades 1.5–2 in; Idaho 2–3 in | Tolerates a higher, less-frequent cut and shade |
When the lawn is rarely dry, mow with a sharp blade and raise the deck slightly to avoid tearing and rutting wet turf.
Northwest mowing calendar
| Month | Mowing & lawn care |
|---|---|
| Jan | Slow growth; an occasional cut on a dry window. Moss keeps growing toward its early-spring peak. |
| Feb | Late winter: address the shade and drainage problems behind moss. Hold off on removing it until mid-March. |
| Mar | Growth accelerates; back to regular mowing. Mid-March through April, dethatch out moss and reseed the bare spots. |
| Apr | Strong spring growth: mow weekly. |
| May | Peak growth; weekly or more. |
| Jun | Continued growth before the dry stretch. |
| Jul | Drier summer: growth slows; mow higher, less often. |
| Aug | Driest month; minimal mowing if unirrigated. |
| Sep | Fall rains return; growth resumes. Overseed thin areas. |
| Oct | Active growth; weekly mowing. |
| Nov | Growth slows; mow on dry windows. |
| Dec | Minimal growth; occasional cleanup cut. |
Mowers & equipment
A sharp blade is non-negotiable for wet NW lawns. See our mowing height guide and best lawn mowers.
Get the full Northwest plan
Lush Lawns Northwest: region-specific mowing heights, seasonal timing, and lawn care for the Northwest (perennial ryegrass and fine fescue).
Printable Northwest lawn care calendar and worksheet
Two PDFs to print at home, built from the extension service publications for the Northwest. Each page lists the publications it draws on.
Northwest Lawn Care Bundle: $5.99
The calendar and the worksheet together, $3.49 less than buying both.
Buy the bundle for $5.99Northwest Lawn Care Calendar: $4.49
Find your grass on the first page, then turn to its page for when to mow, water and fertilize, with mowing heights for each grass.
Buy for $4.49Northwest Lawn Planning Worksheet: $4.99
Measure your lawn, record a soil test, work out how much fertilizer to spread, test what your sprinklers put down, and log the season month by month.
Buy for $4.99Sold through Link, Stripe's checkout, which handles payment and sales tax; the charge on your statement starts with LINK.COM. Your download links arrive by email from support@mowguide.com right after purchase, and each link works for 30 days. If a PDF doesn't work for you, our Refund Policy gives a full refund within 60 days.