In The Dalles, you can get your soil tested locally on Thursdays by Lynn Jones, a Wasco County Master Gardener at:
Sawyer's True Value
500 E. 3rd St.
The Dalles, OR 97058
Soil Sample Collection Procedure
Samples should be taken from the "root zone" of the plants being grown in the soil. The root zone for grass would be 2-3" below the surface of the soil. The root zone for a garden would be 6-8" below the surface. When analyzing a specific area of soil (a lawn, garden, or field) take the sample from several different locations within the area and mix them together. The resulting mix will provide an average that will represent the entire area.
- Use a clean trowel, spoon, or knife to obtain samples.
- Scrape away any mulch, leaves, or material from soil surface.
- Collect a scoop of soil from 3 or 4 locations, several inches down, and place in container.
- The soil should not be touched with your hands any more than is absolutely necessary.
- After the sample is collected (and mixed together), place one (1) cup of it on a piece of clean paper or plastic. Allow the soil to air dry for several hours or overnight. (DO NOT bake the soil to accelerate drying.) All foreign matter should be removed.
- Put the samples in a clean Ziplock bag. The soil sample is now ready to bring in for chemical testing procedures.
The cost is $25.00 for each sample to be tested and can be paid to the cashier when you pick up your results. You will be called when your test is done. Each sample will be tested for nitrogen, phosphorous, potassium, pH, humus and soil texture.
Here you can find a complete list of laboratories serving Oregon.