Copper Spray for Fruit Trees

It's fair to assume that many people have walked in your gardening shoes. All they want to do is grow a thriving fruit tree when they hear that a copper fungicide spray can help keep the tree healthy. It's no joke and no old wife's tale, though it may seem as quizzical to you as imbuing gardening soil with eggshells (for calcium) and coffee grounds (for minerals), but that's how many remedies initially sound. The technique may make more sense to you once you understand how it works and when you hopefully see how your fruit tree responds to it.

Copper Spray for Fruit Trees

The potential for fungal and bacterial disease can put any fruit tree gardener on the defense right from the start, especially if you're anticipating a warm and rainy season that encourages such threats. Copper is a metal, but when it's dissolved and sprayed on a tree, it breaks down fungal diseases, such as peach leaf curl, fire blight, powdery mildew, shot hole and brown rot, says Shonnard's Nursery, as well as pests that burrow into a tree's cracks and crevices.

Copper fungicide spray is used on most types of fruit trees, and while it doesn't come with an iron-clad guarantee, you can increase your chance of success by applying it during a tree's dormant stage, Harvest to Table says. This means that the best window of opportunity exists during the winter or after the tree has turned bare in the fall and before new buds open the following spring. In this way, copper acts as a suppression technique, as it wards against the development of bacteria and fungi. It won't cure an existing disease.

Applying the Copper Spray

Knowing this, you can see where less isn't more; more is more when it comes time to apply a copper fungicide for fruit trees. At the store, the product may be labeled “copper fungicide” or simply “fruit tree spray” or even “orchard spray.” Many varieties require you to mix 1 to 3 teaspoons of copper fungicide with 1 gallon of water before placing it in a spray bottle.

Once you're ready to go to work, the spray should be applied to every square inch of the tree, Harvest to Table says. This means every part of the tree, from the stem and trunk to every branch. Your goal is to literally saturate the surface with copper to blunt any chance of bacteria or fungi from forming.

For added punch, add a spreader-sticker product to the copper fungicide spray. It will perform two essential functions: help the spray spread more uniformly and encourage the tree to better absorb the copper.

Other Application Tips

A few tips may bolster the success of your copper fungicide spray, starting with the conditions outdoors. It should be dry, still and mild – not rainy or windy nor cold or hot. Even a light rainfall can run the risk of diluting the copper, thereby reducing its ability to permeate the fruit tree. Similarly, if it rains during the drying time, which is between four and six hours, the spray should be reapplied. In the end, it's OK if the branches are still moist, but they shouldn't be dripping wet.

Like with other application products, you should read and follow the directions on the label carefully before starting the work. You may be advised to follow the original application with another application two weeks later, in which case you'll want to be sure to have enough copper spray on hand to protect your tree before reaching for your trusty gardening shoes once again.