Digging into xeri-scaping
he one thing anyone can tell you about gardening in Colorado is that it’s not easy. Our unique combination of elevation, soil type and weather conditions presents a real horticultural challenge ” newcomers to the state often find gardening here a frustrating experience, with plants that thrive elsewhere refusing to grow here.
But with patience and a little local knowledge, gardening here can produce incredible results. Brilliantly colored blooms, delicious vegetables and the best lawns in the nation are just a few of the rewards the Colorado gardener may reap.
The art of growing plants in dry conditions is called xeri-scaping, from the Greek word “xeri” meaning dry. There’s not too much you can do to stop the snow from falling or make the air more humid, so soil conditioning and informed selection of plants are the areas on which to focus your attention.
Our soil, tends to be a heavy clay. This type of soil has poor aeration and restricts root growth. With our dry climate, small roots are a big problem as the plant’s ability to absorb what little water is available will be hampered.
Modifiying the soil by adding organic matter is the solution, but it must be done with care. Adding a lot of compost at once will lead to an accumulation of salts around the root base. To overcome this, either select salt-tolerant plants (see “Dig into this on the Web”) or add compost slowly, over a period of years.
Another problem with our soil comes from an unexpected source: lack of available iron. Although our soil is rich in iron, it also has a high calcium content, which makes iron unavailable for plants. Adding more iron to the soil isn’t a good solution as the calcium will immediately begin to render the iron useless to plants.
Instead, select plants that are able to survive in an iron-poor, alkaline soil.
As well as soil limitations, plant selection needs to reflect our climate. Heavy snows will break the limbs of fast-growing, brittle trees such as silver maple or willow. Broad-leafed evergreen plants like mountain laurel and rhododendron struggle with our low humidity, cold wind and bright winter sunlight. If you keep just one thing in mind when choosing plants, it should be this: Go native. Our native plants, shrubs and trees have evolved to cope with everything Colorado can throw at them.
The low temperatures we experience are another important factor affecting the plants we can grow. Again, fast-growing plants and trees will suffer more than slow-growing native species. To reduce the effect of cold air trapped in the garden, try to avoid placing fences and walls on the downslope of your garden. Also, water less in late summer and avoid using nitrogen-high fertilizers at the end of the growing season.
Harry Brooks is an intern with the Vail Daily. He is from England, and does not own a garden.
Thanks to Nancy Buster from the Colorado State University’s Eagle extension office, Mike Bauer from the Eagle River Water and Sanitation District and J.R. Feucht’s article “Colorado Gardening: Challenge to Newcomers” (to view the entire article go to http://www.ext.colostate.edu) for their help with this article.