Soil testing

Asked July 31, 2017, 2:22 PM EDT

Hello. I joined a community garden in Rockaway this year. I was able to get a bed about 3 ft x 15 feet. It has "new dirt" and had compost in it. It was turned over by the boy scouts as a service project.
From the beginning this bed acted odd. We are now at the middle of the season. We had a very wet spring. My zucchini plants are about 18 inches wide, and YELLOW. Other established beds around me are HUGE and deep green. We get good sun from the east most of the day. The bed is elevated. Friend says looks like there is chlorine in the dirt or it needs iron. Where can I get it tested? Radishes made it, beans did not. Dahlia is short and yellow too. Peonie did not come up. Thank you. Robin

Tillamook County Oregon

1 Response

Are you using any nitrogen fertilizer on your bed? Often Nitrogen and Sulfur deficiencies will cause the yellowing you describe. Even when a bed is made from compost and soil, it may cause plants to have a nitrogen deficiency, especially if the organic matter is not very well decomposed. Organic matter that is high in cellulose like wood or straw chips will tie up the available nitrogen until it decomposes better.

Here are some resources for you. The first tells you how to take a soil sample the second is a list of labs in Oregon that will test your soil for a fee. The fees vary some depending upon which tests you want. I recommend that you contact the lab before you send a sample and get any special instructions and agree upon which tests you want. The final one is a resource for organic production.

A Guide to Collecting Soil Samples for Farms and Gardens -

Analytical Laboratories Service Oregon -

Soil Fertility in Organic Systems: A Guide for Gardeners and Small Acreage Farmers -