How to Prepare Soil for Planting

The soils of Ohio are as varied as their geological origin and weathering processes. In some very few areas there is good sandy loam, but most of us have yellow, blue, blue black clays or underlying limestone and shale to contend with. At the risk of over simplifying, it is safe to say that we need to deal with all these soil types in the same way: that is add amendments and work them into a condition good enough to support plant life.

Soils must function in several ways to support plant life. First, they must supply anchorage to hold the plant upright in the ground against all kinds of weather trauma. Secondly, they must hold enough water to supply the plant’s needs at all times of the year. Third, but equally important, the soil has to furnish sites for chemical exchange (minerals and nutrients.) Roots will then have all they need to sustain life and to grow into beautiful plants. The combinations are infinite variable, but luckily, our job is not that complicated.

Start with a bonified laboratory soil test to see if it is necessary to adjust the soil’s chemistry during the preparation process. If so, follow the recommendations carefully. Your local garden center or cooperative extension office will help.
Believe it or not, to loosen and allow drainage in heavy clay, we add organic matter, and to increase the water holding capacity of a sandy soil, we add organic matter. Only the proportions vary slightly. Since most of the functional roots of the plants are in the top 12” of soil, our project is again made easier because we don’t have to dig as deep as once thought, (although soil prepared to 18” is highly advised. We have learned that a wide hole is necessary to accommodate the plant’s roots spread for the first 3 years, before they confront our native junk. Eighteen to twenty-four inches all away around the root ball, or even more, is recommended.

Therefore, whether preparing an entire bed or an individual spot, essentially set the top 2 inches of soil aside for other use. Add 3-4” of organic material. Peat moss is very good, but also well-rotted manures, composted leaves and even old composted mulches can be used. Then turn the organic matter into the soil to thoroughly blend it into the native soil to a depth of at least 12”, but you also must stop short of pulverizing the soil such as to ruin the soil blends structure. There is need for small air pockets in the soil to satisfy the plant’s total needs. Small particles, from the size of peppercorns to a golf ball, are appropriate. By the way, don’t stomp the soil back in around the roots as this also reduces air space in the soil. Just let the percolation of water settle the soil. Don’t be in a hurry at planting time. You only have one chance to work with the plant’s immediate rooting area, so take time to do it right. The following years of profuse flowering and excellent plant growth will be your reward.