The highly plastic clay soils common in the Midwest will exhibit shrinkage when subjected to drying conditions. These types of clay soils will substantially reduce in volume as the clay dries out. This drying phenomenon is often referred to as desiccation. Desiccation can occur following extended periods of hot, dry weather and is often exacerbated or accelerated by the presence of large trees.
Trees with root systems that extend both vertically and laterally can effectively reduce the moisture content of soils supporting a residential foundation system, resulting in a reduction in the volume of foundation support soil. If large trees are present in close proximity to a residence, it becomes doubly important to maintain an ongoing watering program to minimize the effects of desiccation.
When planting new trees and shrubs, they should not be located in close proximity to your residence. Rather, trees should be located away from your home to minimize the impact of root systems on the performance of foundation soils.