Micronutrients in the Garden

Soil in Wheelbarrow SG

Anyone who has worked in a garden for a season or two is familiar with the major soil nutrients – nitrogen, phosphorus, and potassium – or NPK. Fertilizer bags and bottles have the content of these nutrients written in numbers, such as 10-10-10 or 5-2-6. Many of us are also familiar with the secondary nutrients necessary for plant growth – calcium, magnesium, and sulfur. (See my post on Epsom Salt in the Garden for supplementing magnesium and sulfur organically.) Yet, few gardeners are aware that plants must also have eight micronutrients to grow and produce well, and most soil in the U.S. is deficient in many micronutrients. What are they?!

Soil Testing

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. But wait, there’s more!