Following rest satisfaction, plants begin accumulating heat units for growth until full bloom. Again, each variety has a unique number of heat units (called growing degree hours or days). If this number of heat units is small and the tree is in full bloom when temperatures drop, blossoms freeze and the fruit crop is lost.
Finding fruit trees “programmed” with the right chill units and heat units for the Front Range is hard due to the unpredictability of our winter and spring temperatures (the “roller coaster”). While some trees may fruit one year, the crop is lost the next. With many types of fruit, realizing a crop one or two years out of five is typical. This is why there is no substantial commercial fruit industry here and instead it is found on the West Slope where temperatures are moderated.
What are the most reliable fruit tree varieties for the Front Range? Of course some that will grow here have other problems such as how susceptible apple and pear varieties are to fireblight disease. This is the time for readers to step up and tell us their experience. What type of tree fruit do you grow (apple, peach, cherry, plum etc.), what is the variety, what is your crop record (estimated number of crops in the last 5 years), and tell us your Front Range city?
Click comment below and let us know.
[Bowl of apples photo credit Carl Wilson]