Artificial soils provide zip for greenhouse plants

FILLMORE — Trying to dig up some good dirt on gardening? You can stop looking, because the real dirt on growing plants is you may not need it at all.

Today, virtually all greenhouse crops — and many container plants — grow in artificial or manufactured soils.

Many gardeners are now starting transplants, and many more will start containers over the next several months. These are two critical areas where high-quality artificial soils — rather than topsoil — can help you be a more successful gardener.

Topsoil is an endangered commodity in Utah and can be hard to use. When you use topsoil in a pot, it can become rock hard, and the drainage and aeration disappear. Topsoil contains weed seeds, disease organisms and insects, further limiting is usefulness in growing indoor and outdoor plants.

Artificial or manufactured soils, on the other hand, use a variety of products to provide the needed weight, air and water drainage, and water- and nutrient-holding capacity for plants,.

Sun Gro, a major soil-production company for commercial growers in the United States, opened a state-of-the art soil manufacturing and mixing facility in Fillmore in 1995. Dean Daniel, plant superintendent, said the plant makes dozens of standard and custom mixes for growers.

"We do not try to be the cheapest product on the market, but we do try to be the best," Daniel said. All of our products are "rigidly tested and guaranteed so that growers never have to wonder if their plants are going to have a problem with the soil."

Sun Gro tests all the critical factors in the ingredients before adding them to its potting soil. "Salt levels have to be below certain critical levels, or plants are quickly damaged," Daniel said. "Many products — including animal manures — have high salts, so we have to make certain what we add never has a problem."

The company also tests the pH of every batch. The pH is a measure of the alkalinity — or acidity — of a soil.

The real secret of artificial soils, Daniel said, is creating a product that grows healthy, attractive plants. For commercial growers, the key is consistency and quality.

"We keep 12 different mix components in stock," he said. "Peat moss is the basis for our mixes, and that comes from Canada."

Bark is another important part of the company's mixes. "For our commercial mixes, we use fir bark from Montana. We also use bark from Escalante in our homeowner products," Daniel said.

"We get cinders locally from the volcanic rock here in Millard County. The volcanoes just up the road from us are natural wonders. A local firm crushes the material to our specifications, and we add that to our mix."