Testing my garden soil

Asked May 31, 2017, 7:41 PM EDT

Hello, my name is John Turner. I am having a problem with yellowing leaves on my squash plants. Web sites recommend having my garden soil tested by the extension service to figure out what the PH level is and if there is the correct balance of key elements. Do you know where I can have a sample tested and approximately what the cost would be? Thank you in advance for any assistance you can provide.

Washington County Oregon

1 Response

Hello. Thanks for your question. Depending on when you planted the squash, the yellow leaves could be a product of cool soil temperatures. Except for a couple of days, our spring has been exceptionally cool pushing back ideal planting times by 2 to 3 weeks. Soil temperature for planting squash should be at least 60 degrees. Oregon State University Extension has a one-page description of soil thermometers. You can view it at this link.


Nonetheless, knowing your soil pH is invaluable. From time to time Oregon State University Extension provides free soil testing at special events. Right now, none are scheduled. Soil testing kits are readily available at most retail garden stores for a small price. To learn more about soil pH and how to take a soil sample, see this link.


OSU also prepared a list of laboratories that conducted soil testing in 2008. (Of course, availability of services and costs may have changed in the interim.) You can view here.


For additional information on growing squash, two additional resources are attached. The first describes squash pollination.


The second gives guidance are starting squash plants.


Best of luck.