Good soil is the foundation of any successful landscape. Amending your soil with organic matter is the single best method to increase plant health and reduce watering needs.
Soils in our semi-arid, high desert climate range from heavy clay to very sandy, and are low in organic matter and nitrogen. Adding organic matter is the primary method to enrich soil. Simply mixing clay and sandy soil does not create enriched soil. Simply adding fertilizer does not create enriched soil. Fertilizers work more efficiently when the soil has been amended.
Clay absorbs water very slowly but once wet also dries out very slowly. If water is applied to clay soil too fast, it will run off. Adding an organic soil amendment allows for faster infiltration of water. Most soil in Castle Rock is clay.
Sandy soil can absorb water quickly but will drain past the root zone just as fast. Adding an organic soil amendment to this type of soil increases its moisture holding capacity.
Amend your soil
The Town’s minimum recommendations for soil amendment is 4 cubic yards of organic matter per 1,000 square feet of landscape area. This organic matter should be tilled into the soil to a minimum depth of 6 inches. A low-salt organic matter, such as compost, is the best type of amendment. Town standards specify a Class I or Class II compost.
When incorporating amendment into the soil, remove all rocks and construction debris. The amount of organic soil amendment should be appropriate for the plant material selected. Conducing a site-specific soil test will give you specific data for your soil type and plant use. The Colorado State Extension office provides more information on choosing a soil amendment.