Both sour cherries, hardiness zones 4 through 8, and sweet cherries, hardiness zones 5 through 8, can be grown in the state of Colorado provided the trees are planted in full sun in well-drained soil. Sweet cherries grow better in the western, mountainous part of Colorado, although a few of these types can also be grown in urban, eastern areas as well. In the eastern part of Colorado, which is part of the Great Plains, sour cherries are dependable producers.
Western Rural and Urban Areas
Sweet cherries have a warmer growing range, making the western part of Colorado favorable for planting these types. Keep in mind that sweet cherry trees require another tree for pollination and that not all trees will cross-pollinate. The exceptions are Index, Lapins, Stella and Sweetheart, all self-pollinators that work well for those looking to plant one tree, according to the Colorado State University Extension.
Eastern Rural Areas
Sour cherry trees are not only self-pollinators, but are suited for cooler climates like those found in eastern Colorado. Good sour cherry varieties include Montmorency, Early Richmond, Hansen bush cherry, Nanking, Meteor and Montmore. In addition to being self-fertile, North Star and English Morello are double-duty trees because they flower late and pollinate cherry trees that need a partner, according to Alan Buckingham in his book, "Grow Fruit."
Eastern Urban Areas
Urban areas tend to be warmer than surrounding rural areas, due to the urban heat island effect, according to Windows to the Universe, and the cities in eastern Colorado are no exception. Adventurous fruit tree growers can take advantage of the slightly warmer temperatures by planting compatible sweet cherry trees, keeping in mind the rules on self-pollination.