Weed Control · Washington
How to Kill Creeping Charlie and Wild Violet in Washington
Creeping Charlie and wild violet shrug off standard three-way weed killer for two different reasons. Both answer to triclopyr — and to October, not spring.
Regional Hub
Washington Lawn Care
Lawn care built for Washington: Perennial Ryegrass maintenance, regional weed and disease control, and a season-by-season calendar for USDA zones 6b–8b.
Dominant Grass
Perennial Ryegrass
USDA Zones
6b–8b
Soil
Glacial till west of the Cascades (Alderwood hardpan); wind-blown loess over basalt in the Palouse and Columbia Basin
Humidity
Wet cool winters west of the Cascades but dry rather than muggy summers; semi-arid year-round in the east
Weed Control in Washington
All weed control →
Weed Control · Washington
How to Get Rid of Crabgrass: Timing Beats Chemicals in Washington
Crabgrass is a timing problem — but one pre-emergent pass is not a whole season. UF/IFAS: season-long control takes a second application 6–9 weeks later.
Weed Control · Washington
How to Get Rid of Nutsedge: One Pull Does Nothing in Washington
Nutsedge ignores ordinary weed killer because it is a sedge. UC IPM: one pull does nothing — but pulling every 2 to 3 weeks drains the tuber underneath it.
Weed Control · Washington
Kill Dandelions Without Killing Grass — For Good in Washington
Killing dandelions without killing grass comes down to the taproot: the selective herbicides that reach it, and the month they actually work.
Weed Control · Washington
Spring Weed Control: Soil Temp, Not the Calendar in Washington
Spring weed control is decided by soil temperature, not the calendar — a pre-emergent applied two weeks late does nothing at all. The trigger, and the plan.
Lawn Diseases in Washington
All lawn diseases →
Lawn Diseases · Washington
Red Thread: The Lawn Is Telling You It Is Hungry in Washington
Penn State: in most situations red thread is not severe enough to warrant fungicide. It is a nitrogen reading — and the fix is feeding, not spraying.
Lawn Diseases · Washington
Voles in the Lawn: The Runways Fix Themselves in Washington
Melting snow reveals the runways, and the voles usually left with it. Illinois says the lawn regrows by summer — the damage worth acting on is on your trees.
Lawn Diseases · Washington
Lawn Disease After Flooding: What Follows the Water in Washington
Flooding moves the pathogen, stresses the plant and leaves the leaf wet. The hour thresholds that trigger Pythium and brown patch, and why nitrogen cuts both ways.
Lawn Diseases · Washington
Dollar Spot Treatment: The Disease Nitrogen Fixes in Washington
Dollar spot is the one lawn disease caused by too little nitrogen, not too much — the exception to every other fungus guide here. The hourglass lesion confirms it.
Lawn Diseases · Washington
Armyworms and Sod Webworms: Which Ate Your Lawn? in Washington
Green to brown in two days means armyworms; closely cropped patches mean sod webworms. Both are caterpillars — which rules out most grub products.
Lawn Diseases · Washington
Chinch Bugs: How to Confirm Them and What Kills Them in Washington
Chinch bugs: two species, two grass families, and a float test that confirms them in five minutes. Plus the documented resistance nobody prints on the bottle.
Lawn Diseases · Washington
Lawn Grubs: How and When to Kill Them in Washington
Most lawns never reach the grub treatment threshold, so count before you buy — and curative products only work from August through October.
Lawn Diseases · Washington
Brown Patch Treatment: Fungicide Alone Won't Fix It in Washington
Brown patch treatment needs two things: the right fungicide, and the summer nitrogen habit that caused it. Fungicide alone buys you a repeat next July.
Lawn Diseases · Washington
Snow Mold Treatment: It Grew Under the Snow in Washington
Snow mold treatment is mostly about the autumn before: gray and pink snow mold grew under the snow, so what you see in March is already finished damage.
Grass Types in Washington
All grass types →
Grass Types · Washington
Fine Fescue Lawn Care: The Grass That Wants Less in Washington
Penn State lists high nitrogen among the conditions fine fescue is not adapted to — beside heavy traffic. It is the one lawn grass you can spoil.
Grass Types · Washington
Perennial Ryegrass: The Fastest Grass, and Its Price in Washington
Penn State: it germinates in 5 to 7 days and is very competitive with other turfgrasses. Both halves decide what care this lawn costs you.
Grass Types · Washington
Kentucky Bluegrass Care: It Repairs Its Own Damage in Washington
Kentucky bluegrass repairs its own damage and browns in August for the same reason — rhizomes. Mow at 3 inches, feed in autumn, count the dormancy weeks.
Grass Types · Washington
Tall Fescue Lawn Care: Deep Roots, No Self-Repair in Washington
Tall fescue lawn care is one trade-off: the most heat-tolerant cool-season grass, but it never repairs itself and brown patch waits every summer.
Grass Types · Washington
Growing Grass in Shade: The Two-Hour Minimum in Washington
Growing grass in shade has a hard floor: fine fescue is the most shade-tolerant lawn grass and still needs two hours of direct sun. Below that, no seed works.
Fertilizer in Washington
All fertilizer →
Fertilizer · Washington
Winterizer Fertilizer: Right Idea, Wrong Bag in Washington
Purdue backs late-fall nitrogen and faults the bags: rates run too low, the potassium needs a soil test to justify — and warm-season lawns should skip it entirely.
Fertilizer · Washington
Lawn Soil pH: When to Lime, When to Add Sulfur in Washington
Lawn soil pH decides whether lime or sulfur is the fix — and the right answer inverts between Georgia and Arizona. What the soil test number means.
Fertilizer · Washington
When to Weed and Feed: Two Bags Often Beat One in Washington
Weed and feed does two jobs on two different calendars, so one bag rarely times both right. The month it works, and the lawns the label forbids.
Fertilizer · Washington
When to Fertilize: Autumn Matters More Than Spring in Washington
When to fertilize a lawn: autumn matters more than spring for cool-season grass, the reverse for warm-season — plus the state laws that close the window.
Fertilizer · Washington
Why Is My Lawn Yellow? 9 Causes, Not Just Nitrogen in Washington
Your lawn is yellow and nitrogen is only one of nine causes — feeding the wrong one wastes a season. Diagnose by pattern, blade and timing first.
Lawn Care Guides in Washington
All lawn care guides →
Lawn Care Guides · Washington
Dormant Seeding: The Backup Window After You Missed Fall in Washington
Purdue's data: dormant seeding beats spring and trails September only slightly. The rule is cold enough not to germinate — Thanksgiving through March, not October.
Lawn Care Guides · Washington
Lawn Recovery After Flooding: The Clock Starts Underwater in Washington
How long turf survives underwater, why the damage shows up days later, the 1-inch silt rule, and the survival percentage at which replanting beats rescuing.
Lawn Care Guides · Washington
Lawn Ruts After Storm Cleanup: What Repairs, What Doesn't in Washington
Shallow ruts take a ¼-inch topdressing; deep subsoil compaction from heavy equipment on saturated ground is, in Penn State's words, practically permanent.
Lawn Care Guides · Washington
Waterlogged Lawn: Test It Before You Fix It in Washington
Water standing after every rain has four possible causes and they need different fixes. A 15-minute hole test tells you which one you have before you spend money.
Lawn Care Guides · Washington
When to Stop Mowing the Lawn: Watch 50°F, Not the Calendar in Washington
Cool-season grass stops growing when daytime highs stay below 50°F — that's the last-mow trigger. Too tall into winter invites disease; scalping is worse.
Lawn Care Guides · Washington
Winter Lawn Care: The Damage Happens in February in Washington
Penn State: crown hydration is the most common and destructive winter injury, and it happens in late winter after thawing and freezing — not in the deep cold.
Lawn Care Guides · Washington
Summer Lawn Care: What Helps and What Hurts in Washington
Summer lawn care inverts by grass type: feeding a warm-season lawn is routine; feeding a cool-season lawn is the classic mistake.
Lawn Care Guides · Washington
Fall Lawn Care: What to Do, and in What Order in Washington
Fall lawn care is the one season when doing more genuinely pays — for cool-season grass. On a warm-season lawn, autumn is mostly about stopping.
Lawn Care Guides · Washington
How to Aerate a Lawn: Spike Tools Make It Worse in Washington
How to aerate a lawn, and when not to: spike tools compact the soil they punch through, core aeration pulls plugs out, and most lawns need it rarely.
Lawn Care Guides · Washington
How to Fix Bare Spots in a Lawn — Or Leave Them in Washington
A bare spot smaller than your fist closes on its own. The bigger ones are a symptom — and the shape of the spot tells you which cause to fix first.
Lawn Care Guides · Washington
Lawn Mowing Height: Your Deck Setting Is Lying in Washington
Your deck setting is not your lawn mowing height — measure it once and most people find they cut lower than they think. The real number by species.
Lawn Care Guides · Washington
Should You Bag Grass Clippings? It Costs Nitrogen in Washington
Bagging grass clippings throws away up to a quarter of your lawn's nitrogen — and clippings do not cause thatch. The three times bagging is still right.
Lawn Care Guides · Washington
Spring Lawn Care: Do Less, and Do It Later in Washington
Most spring lawn damage is done in March by people being helpful. Spring lawn care runs on soil temperature, not the calendar — and the order matters.
Lawn Care Guides · Washington
When to Overseed Your Lawn — and When Not to Bother in Washington
When to overseed: late summer beats spring for cool-season lawns, most warm-season lawns should not be overseeded at all — and pre-emergent blocks your seed.
Lawn Care Guides · Washington
How Often to Water Your Lawn: Twice Beats Daily in Washington
How often to water a lawn: twice a week beats every morning, and one inch a week beats guessing. Measure your own sprinkler — the timer is not telling you.
Product Reviews in Washington
All product reviews →
Product Reviews · Washington
Best Weed Killer for Lawns: Match It to the Weed in Washington
There is no best weed killer for lawns, only the right one for your weed: the seven chemistries that matter, what each kills, and the one that kills grass too.
Product Reviews · Washington
Organic Weed Killer for Lawns: The One That Works in Washington
The organic weed killer that works on lawns is iron — it burns broadleaf weeds and moss in hours without harming grass. What it won't do: kill the roots.
Washington Lawn Calendar
What your Perennial Ryegrass lawn needs, season by season.
Spring
- Sharpen the mower blade before the first cut
- Mow at 2–3 inches, removing no more than a third of the leaf
- Fertilize mid-May only if the lawn is thin or yellow — ½ to 1 lb nitrogen per 1,000 sq ft
- Aerate, overseed and top-dress thin areas with ¼ inch of compost (April–May)
Summer
- Water about 1 inch a week — or let the lawn go dormant on purpose
- Water a dormant lawn slowly and deeply once in July and once in August
- Keep heavy traffic off dormant turf
- Do not spray herbicide above 80°F — WSU's ceiling, lower than most states
Fall
- Overseed and top-dress thin areas (September–October)
- Fertilize September–October; slow-release synthetic as late as mid-November
- Remove weeds before they set seed
- Lime only on a soil test — never more than 35 lb per 1,000 sq ft per application
Winter
- Stay off frozen or water-soaked turf
- Monitor crane fly larvae in February–March; treat only above 25–30 per square foot
- Expect red thread through the cool wet months — feed it out rather than spraying
- Have mower blades sharpened for spring
Official Washington resources
Three things every guide here eventually sends you to do — and all three answers are specific to Washington rather than national: test your soil, read your own land-grant programme, and check whether the state has added anything to a product's federal label.
Soil testing
There is no public university lab for homeowners here — the state points residents at private labs instead:
WSU list of soil test laboratories (C131)WSU no longer performs soil tests and publishes a laboratory list instead. It names University of Idaho and UMass as university labs whose procedures are accurate for western Washington soils, which is the detail worth having — a lab calibrated for a different region can return a lime figure that does not apply here. Expect roughly $17 to $90 depending on the package.
Why the number matters more than the bag: soil pH in Washington.
Turfgrass research
Every guide here defers to your own land-grant programme somewhere. This is it:
WSU Turfgrass ManagementWashington State University Extension
Set expectations before you go looking: the WSU turf programme is a grass breeding and ecology research operation, led by the Washington Turfgrass Seed Commission Professor and describing itself as in "a transition and re-visioning" — not a homeowner-facing extension arm. It publishes no named homeowner factsheets, cultivar lists or diagnostic services on its own site. For a lawn question in Washington the county Extension office is the route, and for the wet-side problems that define lawns here the neighbouring programmes often publish more than the home state does.
Where their advice and a national rule of thumb disagree, follow theirs — they trialled it in 6b–8b.
Pesticide regulation
Pesticide authority sits with the state department of agriculture:
Washington State Department of AgriculturePesticide Management Division
Restrictions we found printed on labels: Washington product restrictions.
Municipal Watering Restrictions & Microclimates
Hyper-local drought regulations and watering schedules for major metropolitan areas in Washington.
Lawn Health Newsletter
Seasonal lawn reminders, on time
Pre-emergent windows, disease alerts and fertilization schedules for your region — one short email, right when your lawn needs it.
Free forever. Unsubscribe anytime. US lawns only (for now). This season's companion: the printable summer checklist.