Mountlake Terrace is mid-century houses on city lots, with newer buildings near the transit line. The slopes are gentle, the soils are compacted, and the yards were not designed for the amount of roof water a remodels-worth of downspouts can dump. City lawns around here are often a cap of sod over compacted fill. Water runs off or sits in a dish. Cores are how we open that cap without tearing the yard out.
Snohomish County · ZIP 98043 · 2020 population 21,272
Fill dirt that has been driven on for years
Construction fill does not behave like topsoil. It packs under a mower, it sheds a light rain, and it holds a heavy one in a low spot by the foundation. We core twice the first year on the worst of these, spring and early fall, then once a year if the lawn responds.
Small fenced yards mean a walk-behind, not a tractor that cannot get through the gate. We measure the gate before we promise a machine. Seed goes in the holes, not as a scattered hope across a surface that is still sealed between the plugs.
The ground in Mountlake Terrace
Lots are modest. A patio, a small lawn, a side yard that has become a moss strip, and a fence that is older than the owners. That is the usual visit. The soil has been walked on for sixty years. Aeration and dethatching change the lawn more than a bag of seed thrown on top.
Where the lot tips, it tips a little, and a low wall or a re-graded swale is enough. We are not cutting roads into a mountain. Pavers get people off the mud by the back door, and a pressure wash takes the black film off a walk that has not seen sun all winter. Plantings should stay in scale with the house. A hedgerow that needs a lift every year is the wrong tree for a forty-foot lot.
How we do the work
We pull cores, we do not poke holes. A spike aerator squeezes the soil tighter around each puncture, which is the opposite of what a Western Washington lawn needs. Cores are about three inches, left on the grass to break apart in the rain. The visit is timed for soil that is moist enough to take the tine and dry enough that the machine does not leave ruts.
If the thatch is thicker than a finger, aerating through it only decorates the moss. Those lawns get dethatched first. Lime is a separate decision. A lot of local soil is sour, and we spread lime when the lawn shows it, not because a calendar said March.
What we look at first
- Thatch depth before we core
- Whether the ground ruts under foot
- Shade from trees that will keep the lawn thin no matter how often we aerate
- Downspouts dumping onto the same corner every winter
What we leave behind
Plugs on the grass for a few days, then they fall apart. You can mow when they crumble. Watering is only needed if we seeded and the week turned dry, which is rare here. Stay off the soft spots until the footprints disappear.
Seed in the holes
Aeration without seed is enough when the lawn is thick and you are only relieving compaction. When you can see soil between the plants, we put seed in the openings the same day. Seed on an unaerated moss mat is bird food.
What aeration will not fix
It will not move a downspout, kill a cedar’s shade, or drain a dish in the grade. If the lawn fails in the same circle every winter, we look at water and light before we sell you a third visit.
More from this crew
- Lawn aeration across Snohomish County
- Lawn dethatching in Mountlake Terrace
- Lawn seeding in Mountlake Terrace
- Lawn fertilization in Mountlake Terrace
- Lawn mowing in Mountlake Terrace
- Lawn aeration in Lynnwood
- Lawn aeration in Edmonds
- Lawn aeration in Brier
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.
