As with any plant, it is important to pay attention to the cultural practices associated with that plant. Fruit trees prefer full sun but need at least six hours of sunlight a day. With all trees, you must provide adequate irrigation and fertilization — I have yet to see many plants do well with restricted water or nutrients. Trees can bloom and start to set fruit but then have it drop off due to poor irrigation or fertilization practices, as well as compacted soils. Plant new trees carefully. For best growth, limit competition with roots of shade trees, lawn grasses or other vigorously growing plants — try to find a place away from those.
Fruit trees need adequate cold weather to provide the right amount of dormancy so that when spring arrives they can burst forth their blooms. Mild winters can cause delayed or prolonged blooming, which you might think would be good, but it increases the chance of disease transmission and disrupts fruit set. Late spring frosts are the bane of fruit growers as they often lead to damaged flowers. The flowers might look OK, but when inspected up close you see the blackening of interior flower parts such as the pistil. There is not a lot the average homeowner can do, but on nights when the temperature is expected to be below freezing you might try throwing a light tarp or sheet over the tree if the buds are swelling or it’s starting to bloom.
After planting we all desire fruit quickly, but fruit trees require time to start blooming. Most fruit trees have a fruiting variety grafted to an improved rootstock. In some cases, that top portion might only be a year or two old and if this is the case then it could take those fruit trees two to five years to bear fruit. Most fruit trees sold locally appear to be older and larger so fruit production likely could start earlier.
Another cause of poor or no fruit production, even when trees bloom, is lack of pollination. I don’t mean this is due to a lack of bees, rather, it’s whether the trees are self-fruitful, some say self-pollinating, or they are self-unfruitful. Self-pollinating or self-fruitful trees have “perfect” flowers so they can pollinate their own blooms. Self-unfruitful trees require another variety of the species to provide pollen. Self-pollinating fruit trees include most apricots and peaches, European plums and prunes, sour cherries, and some sweet cherries. Self-unfruitful trees include many apples, Asian pears, some sweet cherries and Japanese plums. So if your trees are blooming but not setting fruit you might need to add a pollenizer tree. It’s even possible that bad weather conditions, rain storms, etc., could limit pollination, but that would be pretty rare for us.
What if your fruit trees aren’t blooming? Well, assuming it’s really a fruit tree, lack of blooms could be caused by pruning too much. Trees like nectarines and peaches bloom on longer shoots, but most fruit trees need short shoots or spurs. It does take time to learn how to prune properly so that you don’t cut off too little or too much.
Finally, what is happening when your apple tree bears heavily one year and light the next? In years where apples have a heavy fruit set the development of the apples requires more of the food the tree makes through photosynthesis, which leaves less for good flower bud development. Since the spring buds are developed the previous summer, this can mean less fruit that next year. You can help limit this heavy fruit set one year and light set the next by thinning the fruit heavily during heavy fruit years.
Thought for the day: “Wishing to be friends is quick work, but friendship is a slow ripening fruit.” —Aristotle
Previous articles are available at the Times-Independent website, www.moabtimes.com. Have an idea you’d like Mike to consider writing about? Want more information about these topics? Call the Utah State University Extension Grand County office at 435-259-7558 or email Mike Johnson at firstname.lastname@example.org.