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When to Spray Apple Trees: Insects & Seasons

close up wet apple tree

Apple trees are some of the most iconic fruit trees in the world with each tree yielding hundreds to thousands of apples per year. It’s no wonder that people grow them to enjoy the fruits of their labor! Many people know that you’re supposed to spray apple trees to protect them, but the timing can be elusive. When exactly are you supposed to spray apple trees, and what products do you use? You can spray your apple tree at virtually any time of year, but the time of year will determine what product you need.

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When Should I Spray My Apple Trees?

Let’s check out what products you can spray on your apple trees during each season and what exactly they do.

Winter: Insects & Egg Treatment

During the winter, you can apply dormant oil to your apple trees at the same time you’d prune the tree. Dormant oil is a product composed of water and petroleum or a vegetable-based oil. Neem oil is another popular choice. When applied to the tree during winter, it helps kill wintering insects and eggs, like aphids and mites.

While this is considered optional, we strongly encourage you to not skip spraying your trees with dormant oil for the winter. It will not only kill bugs and eggs but help protect your tree in the long term.

old woman spraying on her apple tree
Image Credit: pamuk, Shutterstock

Spring: Insects & Mildew Treatment

After it’s warmed up, you can spray various insecticides on your trees to kill harvest-ruining pests and mildew. The ideal time to spray is when your flowers have opened, but not yet bloomed. For pests, you can use an insecticidal soap or permethrin. To control rampant powdery mildew, you can use either lime sulfur or a specialized spring/summer horticultural oil.

Summer: Codling Moth Treatment

This is where things get tough. Codling moths are the most pernicious apple pest of all, so you have to take drastic measures to protect your trees. During the summer, codling moths have 2 life cycles, so you have to regularly spray your apple trees with spinosad, esfenvalerate, or acetamiprid. Spray the trees weekly for the entire summer, and regularly inspect your tree for signs of larvae or eggs.

man spraying in an apple tree orchard
Image Credit: branislavpudar, Shutterstock

Fall: Mites & Clean-Up

Use a horticultural oil once a month during the fall to keep mites and other microscopic pests away from your trees. Plus, it’ll discourage other bugs from laying eggs on your trees for the winter. Lastly, you should bag all fruit that dropped to the ground because those apples are a prime breeding ground for next year’s pest population.

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The Best Time to Spray Apple Trees

Season What to Spray For
Spring Insects, eggs, larvae, and mildew
Summer Codling moths and other insects
Fall Mites and other insects
Winter Insects and eggs
apple tree plantation
Image Credit: Tama66, Pixabay

Other Diseases and Insects to Watch For

Depending on your area, you may have to worry about certain diseases that affect apple trees, like fire blight, spider mites, and more.

A few to watch for include:

  • Fire Blight. The disease first affects the tips of branches, turning them reddish brown. If left unchecked, fire blight will race toward your trunk and kill your apple tree.
  • Spider Mites. There’s very little to be done about repelling spider mites but keeping your tree healthy will make them more likely to go after other, weaker trees.
  • Apple Maggots. These pests appear in June and burrow into your delicious apples. Combat them by placing apple maggot fly traps around your tree after spring.

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Apple trees can produce fruit for decades if properly taken care of but pests and diseases can make it difficult. Combat these problems by spraying the correct products for the season, and don’t forget to apply dormant oil for the winter!

Featured Image Credit: Lichtsammler, Pixabay


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