Screened Sandy Loam is the formal name for our Basic Topsoil. Sandy loam is the base material for all of our topsoil blends.
So what exactly is “sandy loam,” and how does it compare to other soil types? We’ll talk about one way that soil is classified and how sandy loam fits into the picture.
This article is the second in a three-part series about topsoil:
- “Choosing a Topsoil Mix for Your Yard & Garden”
- “What is Sandy Loam?: A Basic Guide to Soil Types” (this article)
- “Organic Topsoil from Orting: How It’s Mined”
Classifying Soil Types: The Soil Textural Triangle
The Soil Textural Triangle, seen below, is one way to help visualize the physical differences between types of soil.
You’ll notice the word “Clay” on the left side of the triangle; the word “Silt” on the right side of the triangle; and the word “Sand” on the bottom of the triangle.
Each shape within the triangle represents one of 12 different soil classifications:
- Silt
- Silt Loam
- Silty Clay Loam
- Loam
- Sandy Clay Loam
- Loamy Sand
- Sand
- Sandy Loam
- Sandy Clay
- Clay Loam
- Silty Clay
- Clay
You’ll notice “Sandy Loam” in the list above. In the Soil Textural Triangle graphic, the Sandy Loam section is indicated with a star. It’s located near the lower left corner of the triangle.
How the Soil Textural Triangle Works
On each side of the triangle, you’ll see percentages from 0% to 100%. These numbers represent the percentage of Clay, Silt, or Sand in a soil type.
To learn how the Soil Textural Triangle works, check out this video from Mark Valen, Professor of Horticulture at Southwestern University.
You’ll notice that the percentages of clay, silt, and sand in each soil type changes depending on where you look within its shape. This illustrates the fact that no soil type contains one specific percentage of clay, silt, and sand but a range.
What is Sandy Loam?
Topsoil classified as “Sandy Loam” meets these requirements:
- 60–70% Sand
- 20–30% Silt
- 10–20% Clay
“Loam” is considered the gardener’s ideal proportion of Clay (20%), Silt (40%), and Sand (40%). Sandy Loam, as the name suggests, contains less silt and clay and much more sand.
Our screened sandy loam is a great alternative to loam because it’s more customizable. Screened sandy loam drains well on its own, and it can be amended with compost and manure to create blends that are nutrient rich yet well draining.
On its own, sandy loam is most often used to mound and build up areas of yards or gardens. The topmost layer of the yard or garden are usually finished with richer topsoil blends like 3-Way Topsoil or Garden Mix.
We mix our sandy loam with compost to create bulk topsoil blends better suited for flowers and produce.
Which Topsoil Do You Need?
Check out our article “Choosing a Topsoil Mix” for more information about how to choose which topsoil will work best for your needs.
For more information about Washington Rock’s topsoil products, visit our Topsoil Blends page.
Check out other helpful articles on our blog:
- “Choosing a Topsoil Mix”
- “Organic Topsoil from Orting: How It’s Made.”
- “Clean v. Minus”
- “Comparing Crushed Rock Sizes & Types”
- “How Do I Make a Gravel Surface Wheelchair-Accessible?”
- “How Do I Pick a Gravel Grid Product?”
- “How Many Cubic Yards Do I Need?”
- “How to Find, Vet, and Hire a Contractor Who Can Work with Rock”
- “Should I Put Landscape Fabric Under Gravel?”
- “What are Gravel Grids?”
- “What are the Pros and Cons of Using Gravel Grids?”
- “What Does a Cubic Yard Look Like?”
Washington Rock Quarries is a family-owned business that produces rock, sand, and soil products at Kapowsin Quarry and King Creek Pit in Orting, Washington. To learn more about our products, check out our Products page.