How can a volcanic eruption that happened 30 million years ago help your garden? The answer is Azomite. Now, about that volcano.
Volcanic ash from the eruption settled in a vast seabed in what is now central Utah. This seabed was fed by hundreds of mineral rich rivers. The unique combination of volcanic ash minerals, nutrient rich sea water, and 30 million years created Azomite. Today Azomite is mined, and sold as an organic (OMRI listed) soil amendment for adding trace mineral elements to garden soils.
Technically speaking Azomite (0-0-0.2) is a “highly mineralized complex silica ore.” It supplies soil micronutrients totally from mined sources. These minerals include calcium (1.8%), magnesium (0.5%), chlorine (0.1%), sodium (0.1%). Several grades of Azomite including granulated and ultrafine are available.
USING AZOMITE AND “THE LAW OF THE MINIMUM”
In the world of plant fertilizers there is something called “The Law of the Minimum”. The law states that “plant growth is determined by the scarcest limiting nutrient.” This is where Azomite comes in. While conventional fertilizers deliver macronutrients Nitrogen(N), Phosphorus (P), and Potassium (P), Azomite supplies important micronutrients. Azomite should be used with other fertilizers to create a well-balanced diet for your plants.
Regardless of application, Azomite must be in the plant’s root zone to be effective. Here are some Azomite use guidelines;
Established Beds
Sprinkle Azomite around each plant and work into the soil.
Seedlings and Transplants
Mix a teaspoon of Azomite in the planting hole. Add Azomite to your favorite seed starting mix.
Container Plants
Mix 1 teaspoon per 2-inch pot diameter with potting soil before planting, then give 1 teaspoon of Azomite each quarter
THE AUTHOR’S DIY SEED STARTING MIX
This recipe adapted from the Rodale Institute.
8 Cups Screened Compost
2 Cups Perlite
2 Cups Vermiculite
4 Cups Screened Sphagnum Peat Moss
6 Tbsp Azomite




If more plants are in your future (and when are they not?), you’ll be spending lots of time at your favorite nursery, big box store, and, of course, the Somervell County Master Gardeners Spring 2025 Plant Sale on May 3. While you are out-and-about plant shopping here are some terms you’ll probably see.



the outer seed covering so that the endosperm is exposed but not damaged. Seed scaring takes somepractice. Sandpaper or file can be used to scar seeds. For hard seeds like okra, a toenail clipper works well. Always scar seeds on the side opposite the Hilim (this reduces the chances of damaging the Radicle or Plumule.







