Verified Soil Testing Laboratories

• San Diego County Agricultural Weights & Measures – Verified 6/6/23.
  No longer offer testing services or soil nutrient analysis for San Diego County residents. They suggest use of the appropriate probe to self-test for pH.

• A&L Western Agricultural Laboratories
  1311 Woodland Ave, Modesto, CA 95351
  Phone: (209) 529-4080
  Website: https://al-labs-west.com

• Vert Environmental – Verified 6/6/23
  San Diego Branch, 8316 Clairemont Mesa Blvd Suite 206, San Diego, CA 92111
  Phone: (858) 433-3290
  Email: testing@vertenviro.com
  Website: https://vertenviro.com Click "Services" then "Soil Testing"

• Waypoint Analytical California, Inc. – Verified 6/6/23
  4741 E Hunter Ave., Suite A Anaheim, CA 92807
  Phone: 714.282.8777
  Email: supportca@waypointanalytical.com

Self-Testing: Test kits online and testing

• San Diego Seed Company – Verified 6/6/2023
  Phone: (858) 203-1273 (you may have to leave a message for a call back) or
  Email: info@SanDiegoSeedCompany.com
  Website: https://sandiegoseedcompany.com/product/tools-and-merchandise/laboratory-soil-testing

Soil Testing Information

(Source: UCANR.org)

Soil testing can provide information on your soil’s texture, pH, salinity and the level of essential plant nutrients and fertility. This information may be very useful if you are starting a new garden in an area where plants have not been grown before.

Soil testing may also help you find out why plants are not growing well in an existing garden. A soil test is not always necessary, however, and it will not tell you if poor plant growth is caused by pests or diseases, improper irrigation, or poor cultural practices, such as planting at the wrong time of year.

One of the most useful soil tests is the measurement of soil pH. The test will tell you if your soil is too alkaline or acidic and if corrective measures are needed. A lab can measure soil pH for you or you can do it yourself. A simple pH meter and test kit are available at local nurseries or from mail order companies.

You will only get good information from a soil test if you collect a good sample. To collect soil for testing, dig a small hole 6-8 inches deep with a trough and collect a thin slice of soil from one side of the hole. Put the soil in a bucket and collect more samples from several locations in the garden. Mix the samples together to produce a representative sample from your garden. If you use a commercial testing lab, ask if they will provide a report to help you interpret the results of your soil test. Also ask if they provide recommendations on how to correct soil problems.

File: Testing Labs list - Updated June 23, 2024