By Carl Wilson, Horticulturist with Denver Cooperative Extension
Living in the West has always meant being in touch with the land. Successful Colorado gardeners learn how to take advantage of the favorable plant growing properties of our soils, and how to moderate the less favorable ones through soil preparation.
It may be a surprise to discover that the most important thing to add to any Colorado soil isn't fertilizers - it's organic amendments. Examples of organic amendments are compost, peat and manure.
To amend soils, add a two inch layer of organic material over the surface of the soil and mix into the top four to six inches. This amounts to four cubic yards of organic amendment per thousand square feet of soil area. The same quantity works for any type of planting.
Front Range clays have the advantages of holding water well and being naturally fertile. Their tendency to compact is less favorable for plant growth. Organic amendments shoulder aside tightly packed clay particles to make space for the air so critical to plant root growth.
Sandy Front Range and mountain valley soils drain freely, eliminating plant growth problems from too much water. Organic amendments added to sands act like a sponge to hold enough water for plant growth. Organics also hold fertilizer nutrients - another item often lacking in sandy soils. Rocky, well-drained, mountain soils benefit from organic amendments in the same manner.
With lawns and perennial plants you have a one time opportunity to amend before planting. With annual plantings like vegetables, you can amend the soil every year.Take advantage of opportunities to amend soils with organic material, then carefully regulate the amount of water applied for best plant growth. By doing both, you will realize the greatest results from your gardening efforts.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010