If you live in Teller County, at an altitude of 7,500 feet or above, your USDA hardiness zone is 3-4 with a frost free growing season of 100 days or less. It is important to consider a number of things if you are planning to grow fruit trees in your yard.
First of all, almost all fruit trees are grafted, meaning the root is from one species of tree and the stem and branches are from another.
Second, when buying your tree make sure that the rootstock can withstand long, frigid winters in Teller County. And finally, always plant your fruit trees in the most protected area you can, preferably a south facing aspect, with most trees mulched to retain moisture.
Even with adapted varieties, good management practices are important. Don’t over prune your trees; it can cause slow fruit bearing. Choose trees which give high-quality fruit in cool temperatures and short growing seasons. It usually takes 4- 6 years before an apple tree will bear reliably at high altitudes and they will continue to ripen until the temperatures consistently fall into the low to mid 20s.
Generally having two or more kinds of the same fruit trees will ensure better pollination but make sure they bloom at the same time and keep in mind that fruit trees may not produce uniform crops every year due to environmental conditions.
Spring frost is one of the most serious barriers to tree fruit production in our climate. The damage from frost becomes more serious as the blooms get closer to being fully open, especially in apricots. Open blooms will be damaged or killed a temperatures of 28 degrees or lower. Many people will spray the trees with water, which keeps the temperature at a freezing point and will therefore save some blossoms.
Pie cherries, Chokecherries and other sour cherries are sufficiently hardy for the short-season, high altitude region of Teller County. Pie cherries can bear fruit with only one tree, and will begin bearing in two or three years.
Some kinds of winter hardy pears will also survive in our region but fruit production may only occur in unusually long, warm summers. You also need two kinds of pears for pollination. Personally I would not recommend growing them in Teller County.
American and European plums are generally late maturing and easily dried, jellied, frozen or canned for winter use. Plums must be ripe and harvested before frost occurs but they mature and ripen quickly.
Intense winter sun can cause alternating day/night temperature fluctuations that stress the bark and trunks of young fruit trees, making them crack. During the first two or three years after planting, the trucks of young trees should be wrapped with burlap or white tree fabric wrap to lessen the tendency of damage.
Lastly, protect your trees from wildlife. They rub, chew, and eat the bark of trees, and birds will also join in to eat the fruit. Most deer-rodent sprays are not effective. A fence around the trunk has proven most effective in keeping the pesky critters out of my trees.
Growing anything at high altitude is a challenge but one that is worth it when you harvest the fruit. For more information, visit the CSU extension website at www.ext.colostate.edu.
For questions regarding produce, landscape, and horticulture; please call our growline at 686-7980, visit our website at www.co.teller.co.us/csu or visit our booth at the Woodland Park Farmers Market.