The Stillaguamish sits on the north edge of town, and a lot of the yards along the valley floor are old river ground: fertile when it drains, and a slick gray clay when it does not. Winter rain piles up against houses that back toward the Centennial Trail and the river parks, and the lawn stays soft long after the street looks dry. Clay crusts over after a rain and the seed sits on top. We open the surface and keep the seed in contact with soil that can hold moisture without drowning it.
Snohomish County · ZIP 98223 · 2020 population 19,847
Seed on clay, not on a crust
The right weeks are September and early October, and a careful window in spring if the clay is not still soup. We rough the surface, seed, and press it. A light compost topdressing keeps the clay from sealing over the seed.
We do not seed a low corner that holds water. That corner grows moss and buttercup. Raise it, drain it, or plant something else. The rest of a valley lawn takes perennial rye and fine fescue and fills in before the winter if we are not late.
The ground in Arlington
Arlington is a valley town, not a hillside suburb. Lots near the farmland and the trail are often open to the west wind and sit on clay that holds water. After a wet week the soil smears under a boot and the moss moves into any thin spot in the grass. Houses closer to the river have a second problem: the ground is low, so a downspout that just dumps at the foundation has nowhere useful to send the water.
We plan work around that. Drainage goes in before we talk about a patio or a new lawn. Native plantings that actually belong on this floodplain — vine maple, salmonberry, and other understory that can take wet feet — do better than a plant list copied from a drier lot. Gravel paths and low rock work fit the rural edges of town without pretending the soil is something it is not.
How we do the work
Seed fails here for three boring reasons: it lands on moss, it lands in the dry week of July, or it is a variety that wants a Midwest summer. We use mixes that can take cool, wet winters and our weak sun. The ground is opened first, by dethatching or cores, or the seed is just decoration.
Hydroseed makes sense on a bare area big enough to justify the tank, especially a cleared bench or a new grade. A small backyard is hand seeded or slit seeded. We say which one when we see the square footage, not from the truck.
What we look at first
- Bare soil versus a mat the seed cannot touch
- Sun hours, because no mix grows under a solid canopy
- How the water leaves the area
- Whether hydroseed or a slit seeder fits the gate and the size
Hydroseed, plainly
A slurry of seed, mulch, and tackifier, sprayed on bare soil. It holds on gentle grades better than dry seed. It still fails on a vertical bank, on moss, and on ground that is underwater. We look at those before we book the tank.
The mix we actually use
Perennial rye for speed and wear, fine fescues for shade and for the wet. We do not push a bluegrass lawn that wants heat we do not get. The bag is matched to the light on that yard, not to a single recipe for the whole county.
Water for the first two weeks
Rain usually does it in September. If it does not, the surface needs to stay damp, not flooded. Once the grass is up, we stretch the watering out. A seedling that is misted forever never roots.
More from this crew
- Lawn seeding across Snohomish County
- Lawn aeration in Arlington
- Sod installation in Arlington
- Lawn dethatching in Arlington
- Lawn fertilization in Arlington
- Lawn seeding in Marysville
- Lawn seeding in Granite Falls
- Lawn seeding in Stanwood
Sources for the climate and the water
- USDA plant hardiness map for choosing plants that can take a Snohomish County winter.
- EPA WaterSense on watering less once a lawn or a new planting is established.
- EPA Soak Up the Rain on keeping roof and yard water from becoming someone else’s problem.
