Soil type is discussed in Chapter 2, but you should be aware that soil affects plant hardiness. For example, a Zone 6 plant may be hardy in Zone 5 if it is planted in a sandy loam. However, if the plant is in heavy clay that may retain too much moisture during winter, the plant’s potential hardiness is reduced. Most references provide the recommended soil type for a particular plant. You will most commonly see “moderately fertile, well-drained loam” as the recommended soil condition.
Most Ohio soils are clay and may require amendments or special preparation before planting. Another option is selecting a plant that grows easily in heavy clay soil. The following are examples of plants that grow well in heavy clay soil — northern bayberry, catalpa, flowering quince, burning bush, forsythia, green ash, honey locust, privet, black locust, and Oriental arborvitae.
Soil fertility and pH also affect plant selection and growth rate. Some plants require a regular application of fertilizer, while others survive quite well under low fertility. Likewise, particular trees and shrubs grow better in certain pH ranges. The following are examples of plants that grow best in acidic (pH 5.5 to 6.2) soil — rhododendrons, azaleas, and fothergillas.