Index is a town of 153 people in the Skykomish valley, tucked under steep, rocky walls. Rain comes down those walls in a hurry. Yards are small clearings, and the mountain is the neighbor on every side. On a slope, an aerator is how you rut a bank and start a rill. We core the ground that is actually flat enough to mow, and we leave the hillside alone.
Snohomish County · ZIP 98256 · 2020 population 153
Only the flat bench gets cored
Rocky, thin soil stops a tine early. Forcing the machine just chatters and rips the turf you have. We walk the bench of the lot, mark the part that drains instead of shedding, and core that. The bank needs a drain or a wall, not plugs.
The season is shorter up against the Cascades. We do not aerate into a freeze or into a week of mountain rain that will turn the cores into mud on a slope. If the lawn is mostly moss because the soil is two inches over rock, aeration is the wrong tool and we will tell you.
The ground in Index
There is no subdivision playbook here. Access can be a single lane, the soil is thin over rock, and a “backyard” may be forty feet of level ground before the timber starts. Intense runoff is the design constraint. A wall has to be heavy enough to stay put, and a drain has to daylight somewhere that does not wash out the next switchback.
We keep planting short and native. Anything that needs summer water and a gardener will lose. Gravel and hardscape earn their place because they stay usable when the ground is soaked. Pruning and cleanup are how you keep the forest from taking the roof, the line of sight on the drive, and the ditch that is supposed to carry the runoff.
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
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 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.
When we show up
The useful months are April into early June, and again in September. Midsummer cores on a dry lawn shatter and the holes collapse. January cores on saturated ground are ruts. We would rather wait a week than leave you with tracks.
More from this crew
- Lawn aeration across Snohomish County
- Lawn dethatching in Index
- Lawn seeding in Index
- Lawn fertilization in Index
- Lawn mowing in Index
- Lawn aeration in Gold Bar
- Lawn aeration in Sultan
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.
