Whether you decide to plant directly into your ground or in raised beds, you will need to test your soil to be sure it has the correct pH and enough nutrients to support your plants. Soil testing is recommended at least annually, but if you have problems with your soil, you may wish to test more often. (I test twice a year.) There are two ways to do this. You can have your soil professionally tested or you can test it yourself with a home soil test kit.
If you wish to have your soil professionally tested, your local college agricultural extension is a great resource. Here in South Carolina, Clemson University has an agricultural extension that will do soil testing for any resident for about $6/sample (as of this writing). Professional soil tests will give you information regarding pH along with the primary nutrients nitrogen, phosphorus, potassium (NPK); the secondary nutrients, such as calcium, sulfur, and magnesium; as well as micronutrients, such as manganese and zinc. (By the way, your local college extension is a also great resource for growing information specific to your local area.)
If you have raised beds, you will have to soil test each bed. That’s not as important when you first get your soil because the same soil is going into each bed. However, after your first growing season, the soil nutrients will be different in each bed because different plants utilize different amounts of nutrients in the soil. Because I have 14 beds, professional soil testing would get a little expensive! So, I decided to test my soil with a home kit.
There are quite a few home soil test kits available, and I wasn’t sure which to use. I’m not a chemist, but my father is; so I asked him. I now use what he does: Luster Leaf Rapitest Soil Test Kit. It tests for pH as well as NPK and comes in packages with 10 tests for each. The instructions are very easy to follow, and the package includes a chart of vegetables, fruits, flowers, etc. with their recommended pH levels as well as recommendations for amending your soil based on your results.
The instructions tell you to put one cup of soil in a container with five cups of water. If you have one sample, that would be okay. However, I’d need 14 very large containers! So, I use plastic cocktail cups (see photo above) that I get at the dollar store. Don’t forget to mark your cups so you know where the soil came from! As long as you keep the ratio of one part soil to five parts water, the test will work correctly. I use two tablespoons of soil to ten tablespoons of water in each cup.
Once you’ve received your test results – either from a professional test or your own test – write down the results in your gardening log for future reference. It will also be great to see how your soil changes as the seasons pass.