Which topsoil or soil mix is best for your lawn or garden? In this article, we discuss the differences between our four residential soils.
Washington Rock’s topsoil is mined and produced at King Creek Pit. True to its name, the topsoil sits on the surface. We separate topsoil from the sand below it. Then we used special equipment to remove larger pieces of gravel from the topsoil. You can see each of our residential soil products compared side by side below.
Our Basic Topsoil is a screened sandy loam. If you look at the Soil Texture Triangle below, you can see how much sand, silt, and clay our sandy loam has compared to other soils.
Sandy loam contains a large amount of sand and a little bit of silt and clay. It drains well, and plants grown in it need to be watered more frequently. Basic Topsoil is a great material to use to mound and build up areas of your yard.
Our 3-Way Topsoil is a blend of clean sandy loam and compost. It’s a great choice for flower beds, gardens, and new lawns. Our product meets the planting bed soil requirement for Post Construction Soil Quality required by Pierce, King, and Thurston counties.
Check out our video about how we make 3-Way Topsoil below.
Wanting to build a rain garden? Our Bioretention Soil Mix is just what you need. It’s a blend of 60% well-graded sand and 40% fine compost. It is free draining, and the compost helps retain moisture. The City of Seattle uses the same blend around retention ponds and in gardens on high-rise buildings.
If you’re looking for something hardier, try our Garden Mix. It’s a blend of 50% clean sandy loam and 50% organic yard waste compost. It’s an excellent choice for gardens and raised planter boxes. It drains well and provides lots of nutrients for plants and vegetables.
For more information about Washington Rock’s topsoil products, visit our Topsoil Blends page.
This article was originally published in March 2017 and was updated in April 2022.