Soil for raised beds

Raised beds are the answer to a lot of gardener’s prayers. The soil warms up quicker for planting in the spring, it isn’t compacted from foot traffic, and the beds are easy to maintain. However, for the best performance, the soil you fill them with should match your climate, your native soil type, and what you plan on growing.

Bob Polomski is an Extension horticulturist at Clemson University. He says do not use soilless potting mixes designed for container gardening.

"They contain perlite and peat moss, vermiculite. These are great materials for containers, but once you go out into the garden and you start incorporating these soilless, bagged materials, you create havoc in that environment," says Polomski. "You mess up the soil pH, you affect mineral availability, you also affect drainage."

Work with your native soil and add well-composted organic amendments to it such as grass clippings, leaves, and pine bark. The first step in filling the bed is to decide where the pathways around it will be.

"We could take soil from the pathways, incorporate them into the middle, which is going to be our raised bed. And then also at the same time as I move that soil, I’m adding organic material. I’m figuring about 2” of this material across the entire length of the bed, and then incorporating that to a depth of 8”-12” would be ideal," he says.

At the end of the growing season, put in a cover crop or add mulch to the bed so it can be incorporated into the soil next spring. Also be sure to test your soil so you can adjust the pH or add any minerals that are deficient before you plant.