Updated 18 July 2023

By now, we’re all familiar with fertilizer when it comes to growing garden vegetables and flowers. When the cotyledon leaves appear on your seedlings, it’s a sign your young plants have used their reserves. Its roots are now searching for additional nutrition in the soil. Adding fertilizer doesn’t just improve the growth of your garden crops, it is essential for healthy growth and production. Yet, when it comes to microgreens, one doesn’t talk much about fertilizers. Couldn’t microgreens use fertilizer to improve their growth, just like garden seedlings? We say yes—you just need to know which fertilizers are the most ideal for microgreens and how to use them.

We suggest using either Azomite, a water-soluble trace mineral fertilizer, or another fertilizer, such as FloraGro. Both provide essential nutrients to your seedlings—and in this case, your microgreens. Keep in mind they are applied using different methods.

Azomite

A fine powder mined from a volcanic ash deposit that contains a myriad of rare earth elements and trace minerals. We recommend mixing azomite in with your compost and incorporating that compost into your potting soil for microgreen growing. Or, just mix it directly into the potting soil you will be growing with. Mixing it in beforehand allows the Azomite to process and break down for better consumption by your microgreen plants. Apply 1 tablespoon per 10x20 tray or 1 teaspoon for every 2 inches of your pots diameter.

FloraGro

A water-soluble fertilizer containing nitrogen for structural and foliar growth. Wait until your microgreens are poking out of the soil and the cotyledon leaves are spreading apart, reaching for the light. Then, fill a cap full of fertilizer and mix it into a gallon of water. We recommend bottom watering at this point. This fertilizer won’t burn your seedlings like other garden mixes may.