What Is High Altitude Gardening?

Soil Concerns

• Because the climate of high altitudes is generally dry and cool, vegetation is limited. As a result, less organic material decays and enriches the soil, leaving a relatively shallow layer of topsoil available for plants. The underlying soil varies depending on where you live. Colorado for instance has heavy, clay soil while Idaho high desert areas have silty and sandy soil under the thin topsoil.

Cold Temperatures

• The higher your altitude, the colder temperatures you have year-round and the more likelihood exists for frosts that can damage plants. You can work around this phenomenon by planting native plants that tolerate the cold temperatures, harvesting crops early to thwart the effects of heavy frosts, irrigating the soil prior to frosts and keeping a supply of crop covers on hand.

Short Growing Season

• Cold temperatures in high altitudes mean the growing season is not as long as it is at lower elevations. Fortunately, most vegetables come with short-season varieties that mature before nights grow too cold. While many plants grown at higher elevations can only grow as annuals, the intensity of sunlight at high altitudes, which can sometimes cause problems for plants, also produces flowers with strong stems and brilliant flowers.

Low Humidity, High Winds, Intense Sunlight

• Low humidity, high winds and high intensity sunlight characterize high altitude climates. All of these conditions cause plants to lose water more quickly than they would in more benign conditions, leading to smaller plants and slower rates of growth at high elevations. On a more positive note, the low humidity discourages plant diseases and the rapid growth that some plant pests rely on.

Plant Choices

• Different high altitude areas support different plants. Blue oat grass (Helictotrichon sempervirens) provides a deer-resistant perennial for U.S. Department of Agriculture zones 4 through 8. This clumping, 2 1/2-foot ornamental grass with blue-green narrow leaves gives a garden interesting form and bright fall color. An array of primroses (Primula) fit well into an alpine rock garden because they do well with cool summer evening temperatures and thrive in USDA zones 4 through 8.