All major population centers in Colorado are partially located on expansive soils. These soils, called bentonite, contain a clay mineral that swells when it gets wet and shrinks upon drying.
Swelling soils cause damage to thousands of homes every year. The extent of the damage varies from cracked driveways and sidewalks to severe structural deformation. There are several practices that will allow you to grow a landscape that complements your home, while avoiding the potentially damaging effects of swelling soils and perhaps mitigate the damage to your home.
Begin landscaping with a site that has been graded so water drains away from the house. Plant vegetation no closer than five feet from the foundation, unless the plants have very low water requirements. Xeriscape-type groundcovers and mulches are especially useful near houses because they can help reduce extreme moisture fluctuations.
Don’t allow sprinkler systems to spray any closer than five feet from the foundation, and plant trees no closer than fifteen feet from the foundation. It is important to carefully regulate water applied near the foundation. Avoid the temptation to remove downspout extensions to harvest water for flower beds near the house.
For more information, see the following Colorado State University Extension fact sheet(s).
- Mulches for Home Grounds
- Xeriscaping: Creative Landscaping
- Xeriscaping: Trees and Shrubs
- Xeriscaping: Ground Cover Plants