Mercer Island sits in the middle of Lake Washington, so almost every street runs downhill to the water. Lots are steep, the tree canopy is old and tall, and the shoreline lots have banks that move when runoff from the street above has nowhere else to go. Sod run to the water’s edge is fertilizer, soil, and a slipping mat. We stop the lawn short and plant the bank.
King County · ZIP 98040
Keep the sod off the bank
The upper yard can be sodded like any damp county lawn, with extra care that the grade does not send water and fines downhill in a sheet. We build a break, a bed, or a drain between the lawn and the shore.
Watering new sod is heavier than a finished lawn. We set it so you are not washing the prep into the lake. If the only place you wanted grass was the soft bank, we decline that part.
The ground in Mercer Island
Most of our work here is on slopes. A patio or terrace has to be cut into the hill with a real base and a drain behind any wall, or the first wet winter shows where the water wants to go. On the lakefront lots we keep native shrubs on the bank, because they hold the soil better than lawn, and we take runoff to a drain or a rain garden instead of letting it sheet over the edge.
The city is strict about removing large trees and about work near the shoreline. We check what needs a permit before we cut or dig, and we plan around the trees you have to keep. Under those firs and cedars the ground is shady and mossy, so we often turn worn-out lawn into planting beds and stone paths that stay clean year-round.
How we do the work
Sod is instant cover and a slow root. It dies when it is laid on compacted clay, on a moss mat, or in a low spot that stays wet. We strip or till, we fix the grade so water leaves, and we lay tight seams on soil that has been loosened a few inches down.
The first two weeks are water and no traffic. After that we want roots chasing soil, which means less frequent watering. A sod lawn that is sprinkled every day forever is a sod lawn that peels up in August.
We lay what arrives that day. Sod that sits on the pallet through a warm afternoon cooks in the roll, and we will not install it.
What we look at first
- What is under the old lawn
- Grade and where the roof water goes
- Access for the pallets
- Sun, because sod in deep shade is an expensive way to grow moss
The first two weeks
Water enough that you cannot peel a corner up by the end of week two. Stay off it. Mow the first time at three inches once it resists a tug. Then ease the water back so the roots leave the roll.
When seed is the better buy
Large areas, deep shade, and tight budgets that would force us to skip prep. Seed costs less and roots deeper if you can wait a month. Sod is for the yard you need to use, on soil we were allowed to prepare.
What is under the roll
A few inches of loosened soil and compost, graded to leave the house. Not the old lawn. Not landscape fabric. Not a sand bed that turns into a pan. If we cannot prep, we should not lay sod.
More from this crew
- Sod installation across the region
- Lawn seeding in Mercer Island
- Lawn aeration in Mercer Island
- Landscaping in Mercer Island
- Lawn fertilization in Mercer Island
- Sod installation in Sammamish
Sources for the climate and the water
- USDA plant hardiness map for choosing plants that can take a King 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.
