Successful Colorado gardeners learn how to take advantage of the favorable properties of our soil and how to improve it through soil preparation.
The most important thing to add to any Colorado soil isn’t fertilizer; it’s organic materials like compost, peat and manure. Organic materials are also known as organic amendments.
To organically amend soil, add a two-inch layer of organic material over the surface of the soil and mix it into the top four to six inches. Add four cubic yards of organic amendment per 1,000 square feet of soil area.
Clay soils hold water and are naturally fertile but have a tendency to pack, which can hinder plant growth. Adding organic materials loosens tightly packed clay particles to make space for the air, which is critical to plant root growth.
Sandy soils drain freely, eliminating plant growth problems from too much water. But sometimes plants in sandy soil don’t get enough water. Organic amendments added to sandy or rocky soil act like a sponge to hold enough water for plants to grow. Organic materials also hold fertilizer nutrients, another item often lacking in sandy soils.
Before planting lawns, trees and shrubs, add organic materials to the soil. Where perennial and annual plantings like flowers and vegetables are grown, the soil can be amended every year. For the best results, amend soils with organic material and then carefully regulate the amount of water given to plants.
For more information, see the following Colorado State University Extension fact sheet(s).
- The Science of Planting Trees
- Perennial Gardening
- Vegetable Garden: Soil Management and Fertilization
- Choosing a Soil Amendment
- Xeriscaping: Creative Landscaping