SOIL

Do a soil test!

A first important step in determining what plants will likely be successful in your garden is determining what kind of soil you have. Some plants are very picky about their soil, so not every native plant will thrive in every garden. Manzanitas need sand, while California wildroses prefer clay. Follow these steps to determine what kind of soil is in your garden so you can choose the right native plants for your soil.

Step 1: Fill a jar one-third full with soil from your garden. Make sure to remove sticks, rocks, and other debris.

Step 2: Fill the remainder of the jar with clean water and shake well until the soil is fully mixed with the water.

Step 3: Let the jar rest for one minute. The sand will sink to the bottom. Mark a line above the sand with a permanent marker.

Step 4: Let the jar rest for 2 hours. The silt will now layer on top of the sand. Mark this new line with a permanent marker.

Step 5: Let the jar rest for 2 days. The final layer, clay, will settle on top. Mark this line with a permanent marker.

Step 6: Take a ruler and measure the following:

• Bottom of jar to clay line

• Bottom of jar to sand line

• Sand line to silt line

• Silt line to clay line

Step 7: Calculate your percentage of each section:

• (Bottom to sand)/(Bottom to clay) x 100 = % Sand

• (Sand to silt)/(Bottom to clay) x 100 = % Silt

• (Silt to clay)/(Bottom to clay) x 100 = % Clay

Step 8: Use the diagram on the top of the next page to determine your soil type.

Photo Examples

1. Claire’s Garden: Clayey – very slow draining
   Sand: 26% Silt: 0% Clay: 74%

2. OVLC Office: Loamy – medium draining
   Sand: 30% Silt: 42% Clay: 28%

3. Oso Trailhead: Sandy – fast draining
   Sand: 70% Silt: 19% Clay: 11%