Soils in Colorado and other parts of the country are often poorly suited for perennial gardens. Then tend to be either sand or clay--nothing in between! In either case they are almost totally lacking in organic material. The addition of organic amendments to either soil type will create a better environment for any type of plant roots. In sandy soils, organic amendments act as a sort of sponge to help retain moisture. In heavy clay soils, they help to loosen the soil and create air pockets-–a necessity for healthy roots. Therefore, compost or sphagnum peat should be added by either layering it on top of the soil and tilling it in, or by working it in plant by plant. On a large scale, three to four cubic yards of amendment per 1,000 square feet of planting area is recommended; or it may be spread to a depth of 1.5 to 2 inches and then tilled in. If done by individual plants, the holes should be dug wider than the root ball of the plant. The soil being replaced around the roots should be roughly 2/3 existing soil worked together with 1/3 amendment. For more detailed information, see fact sheets:
Colorado Gardening: A Challenge to Newcomers
Choosing a Soil Amendment
Composting Yard Waste

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