This guide on apple tree care will help you get the most out of your tree. Apples do well in Colorado, and are a very popular choice along the Front Range. However, if neglected, they will revert to “the wild” and yield poor fruit. There are some important pests to look out for, and pruning is essential for good fruit, but a well cared for apple tree will reward you with a bounty of fresh produce every fall – well worth a little bit of work! Apple Tree Pruning Pruning apple trees is such a big subject, it deserves its own article (coming soon!). Apple Tree Insects Codling Moth What’s worse than finding a worm in your apple? How about half a worm. Codling Moth larvae are the “worms” in apples, and they are a major pest in Colorado. Any untreated tree will have plenty of these pests. They can be difficult to control; orchards typically spray once a week throughout the entire season! We find that two or three well-timed sprays can be sufficient for the homeowner. The sprays we use are approved for use on food crops and are also approved for use in organic gardening. Please be aware that some local tree services still spray apple trees with chemicals NOT approved for use on food. Another note: Codling Moth traps are widely available at nurseries and garden stores, but these do not work to control the moth. Rather, they are an indicator of when and in what quantity moths are present. Woolly Aphids AKA Fuzz Bugs and Fluff Butts, these aphids are “woolly” because they are covered in white, cottony “hairs”. These aphids are found along twigs and small branches (and sometimes on the trunk), rather than on leaves. They also are more damaging than most aphids because they suck sap right out of the tree’s nutrient transport system. We do a dormant oil spray in late winter to control woolly aphids. Apple Maggots We keep our eyes open for these guys, but they are more common in eastern Colorado. Apple Tree Diseases Fire Blight This is the most serious threat to the health of your apple tree. Fire blight is a bacterial disease that causes branches to look scorched, with leaves turning black and crispy. It spreads like fire, too. Left unchecked, this disease will kill susceptible trees. Two or three well-timed treatments in the spring can keep fire blight from progressing. Any diseased tissue needs to be pruned out by someone with experience. Some apple trees are resistant to fire blight. Powdery Mildew On most plants, powdery mildew is not a major concern, but this powdery-looking fungus can scar apple fruits and also kill flowers- affecting fruit production. Powdery mildew can be kept in check with a twice-per-year non-toxic spray and by raking up leaves and fallen fruit from under the tree. Cedar Apple Rust Cedar Apple Rust doesn’t really hurt the tree, so we don’t worry about it too much. This is a fungus that leaves circular rust-colored spots on the leaves of apple trees and hawthorn. Again,it’s mostly a cosmetic problem, and it’s also very difficult to control. Improving Apple Tree Fruit Fruit Thinning When you reduce the quantity of the fruit, you increase the quality, assuming the tree is reasonably productive to begin with. Thinning the fruit is easiest to do when the fruit is first forming: when it’s about the size of a grape in the spring. Leaving only 1 fruit to develop every six to eight inches will give you larger, juicier and sweeter fruit later on. It can be a lot of work, but it is one of the simplest ways to get better apples from your tree. My friend says it’s good therapy, so that’s a bonus too. Sanitation Sanitation means cleaning up underneath the tree, where insects, bacteria and fungal spores can hide out. Rake up fallen leaves and fruit in the fall for a healthier tree next spring. Watering&Fertilizing Apples can suffer problems from both over watering, and under watering. A good deep soak all around the tree once a month to every three weeks in the summer should be enough water. Try not to wet the leaves, as that is how fire blight spreads. A balanced fertilizer applied once or twice per year can improve fruit production. Too much Nitrogen will cause only leaf development, so be sure to use a balanced fertilizer. Pollination Some apple trees are self-fertile: they don’t need to be cross-pollinated by another tree. But most apple trees do need a pollinizer to produce fruit. A pollinizer is another apple tree that can lend some pollen, and a pollinator is the animal (fly, bee, moth or bird) that transports the pollen. Fortunately, there are so many apple trees in and around Fort Collins that this is usually not an issue. If this is an issue with your tree, you can cut some small flowering branches off a friends apple tree and stick them in a vase with some water next to your flowering tree. You (we) could even graft a branch from another apple onto yours. Problem solved. Early Frosts Apples tend to bloom late enough in the season that their blooms don’t get killed by early frosts (this is common with early bloomers like peach and apricot), but it can still happen. If a frost is expected while your apple is in bloom, one option if the tree is small enough is to cover it with a frost blanket, available at many nurseries. This is often enough to protect the blooms through the night. For more apple tree care tips and advice, or to request a free consultation, call 970-690-0769
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