As plants grow they tend to gobble up all the nutrients in the soil leaving it stripped of nourishment. Using organic fertilizer that releases them slowly back into the soil provides a steady and continuous flow of replenishing minerals. Organic fertilizers not only have a positive impact on the health of your soil, they also keep your ground water in good shape. But it can be tricky to know which bag is the right one for your garden.
The plant food pyramid consists of three main food groups: nitrogen, phosphorous and potassium (sorry, no cookies and ice cream here). Each bag of fertilizer comes with a label of three numbers that indicate the fertilizer’s nutrient ratio—for example, 5-10-5, 12-12-12 and 4-12-0.
The first, second and third numbers always represent the same nutrient. The first number indicates the percentage of nitrogen (N), the second represents the percentage of phosphate (the type of phosphorous, P2O5), and the third number indicates the percentage of potash (the form of potassium used, K2O). So a 5-10-5 fertilizer contains 5 percent nitrogen, 10 percent phosphorous and 5 percent potassium.
You might still be thinking, “Okay, now I know what the numbers on the bag mean, but I still don’t know which combination is the right one for my soil.” A simple soil test is a great way to find out the nutrient makeup of your soil and eliminate any guesswork. Lowe’s offers an easy to use and cost effective option that also includes a pH test, or Gardener’s Edge offers a slightly more expensive electronic version.
For more ways to make that green thumb even greener, check out our other sections on soil type, mulching, watering your garden and more.