Organic soil is a must
Good soil is the foundation of any successful landscape. Amending the soil in your landscape with organic matter is the single best action you can take 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. Enriched soil provides nutrients for stronger roots and helps retain moisture requiring less water.
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 soil with compost
The Town of Caslte Rock recommends adding organic compost, such as Class I or Class II, that has low-salt content. Till a minimum of 4 cubic yards of organic matter per 1,000 square feet of landscape area into the soil a minimum depth of 6 inches.
For established lawns, add a light layer of compost after annual aeration. This step may be needed for several years to attain an adequate volume of compost into the soil.
Soil tests are recommended to provide specific data for your soil type and plant use. Check the Colorado State Extension office for more information on choosing a soil amendment.