Fruit Tree Spraying

Fruit Tree Spraying

Fort Collins organic fruit tree spraying service

ArboRx is the area expert in caring for fruit trees, with an organic approach.

Many people in Fort Collins, Loveland and Windsor have fruit trees, with apples, peach, plums, apricot, pear and cherry being some of the most common. These trees tend to do pretty well here, and apples especially can put out a good crop of quality fruit without much extra care. Though, in terms of insects and disease, there are some common problems that these fruit trees have.

Because most homeowners enjoy eating at least some of the fruit their trees produce, I never use any sprays that aren’t approved for use in organic gardening. That means if I ever spray your fruit tree, I use OMRI (Organic Materials Review Institute) Listed products. See the tree spraying page for more info on the Organic products I use.

Below I’ll go into more detail in some of the issues fruit trees in our area have.

Common problems of fruit trees:


Fire Blight is a bacterial disease that affects apple and pear. It can spread quickly and left unchecked can lead to the death of the tree. It’s easy to spot as leaves and fruit appear scorched, as if by fire. It can be controlled through careful pruning and springtime spraying.

fire blight on apple tree

Fruit Tree Aphids

Aphids are common pests of all fruit trees and usually cause the leaves to become stunted and curled. Each species of tree has it’s own species of aphid associated with it. Organic treatments include sprays of soap or oil.

fruit tree aphids causing leaf curl


The most common fruit tree borer in Fort Collins is the Crown Borer, which targets plum and peach right at the base of the tree. There are other borers as well such as the shot-hole borer, most of which seem to go after unhealthy trees. A well-timed spray of Acelepryn is an effective organic treatment for Crown Borer.

unkown fruit tree borer

Codling Moth

If you’ve ever bitten into an apple and found a worm (or half a worm), chances are it’s a codling moth larvae. Extremely common in Northern Colorado, several treatments are needed each year to effectively control codling moths.

codling moth larvae found in an apple

Diseases of the wood

This image shows what Fire Blight looks like when it gets into the wood. There are actually many wood diseases; fruit trees seem especially prone for some reason. Phytopthora, Cytospora, Coryneum Blight, Coral Spot, crown rot and the list goes on. Keeping the tree healthy before disease sets in is the best management strategy.

Fruit tree wood diseases often show up as discoloration

Improving Fruit Quality

So let’s say you have some fruit trees, but you’re not getting much out of them. We should be able to improve that. The first step is to identify at what point the problem starts.

  • Does the tree flower? If not, it can’t make fruit. Sometimes trees won’t flower when stressed, if they lack in Phosphorous, or if there is a late frost. Also too much shade can cause few flowers.
  • If the tree does flower, does it begin to form fruit? If not, I would suspect lack of a pollinator. Some fruit trees are self-fertile, but many need to be pollinized by a seperate compatible fruit tree. Not only is a pollinizer (pollon donor) needed, but also a pollinator, such as bees.
  • Fruits begin to form, then stop. Inspect for signs of disease, such as Fire Blight or mildew. If some immature fruit drops from the tree in early June, this is normal; it’s just the tree shedding some weight.
  • Biennial cropping. This is when you have a bumper crop one year, and a small crop the next. Apple trees especially will fall into this every-other-year cycle if they aren’t pruned and thinned regularly.

Getting the most out of your fruit trees usually involves implementing a complete management program that addresses everything from pruning, to insect and disease control, to proper watering and fertilizing. Although this all probably sounds very daunting, it can be as simple as having myself stop by a few times a year to take care of things as needed. I keep an eye on my customers trees and take care of any issues that may arrise, and prioritize treatments to fit your budget.