What’s wrong with my apple tree?

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Getting helpDiagnosing the problem is the first step in finding a solution for your apple trees.

University of Minnesota Extension has useful tools to help you learn about your tree’s health and resources for solving problems with apple diseases as well as many other gardening challenges.

For more on integrated pest management for apples in the home garden:z.umn.edu/applepest

For more about growing apples in your home garden:z.umn.edu/appleshomegarden

What’s wrong with the leaves on my apple tree?

Apple scabis the most common disease of apples in Minnesota. It is caused by fungus that affects leaves and fruit. It can spread from ornamental crabapple trees.

Cedar apple rustis a fungal disease that causes red-orange spots on top of leaves and fuzzy spores on the underside. Infections can come from red cedars planted nearby.

Fireblight is a bacterial disease that can a kill tree if not managed. Shepherd’s crook shoots (branches that curl in at the ends) are a telltale symptom.

Other diseases affecting leaves: � Black rot � Drought � Iron chlorosis � Honeycrisp zonal chlorosis

What’s causing spots and bumps on my apples?

Apple scab,as noted before, is caused by fungus that affects leaves and fruit. Prevent by pruning and cleaning up dropped leaves and fruit in the fall.

Apple maggotare small white worms that cause lumpy fruit. Prevent by bagging fruit in June to trap insects, then discard all dropped leaves and fruit in the fall.

Hail damagecauses dark spots and depressions on fruit. If skin is broken, remove fruit to prevent wasps and fruit rot.

Other causes of spots and bumps: � Bitter pit � Fly speck � Plum curculio

Why doesn’t my apple tree have any fruit?

Apple trees have to be at least 3 years old to start bearing fruit. � Some varieties start bearing fruit later

than others. � Rootstock affects how soon you’ll get

fruit. � Dwarf: 2–3 years after planting � Semi-dwarf: 3–5 years after

planting � Standard: 5–8 years after planting

Apple trees are naturally biennial.If a tree produces a big crop one year, it will not have the energy to set fruit buds for the following year.

Fruit should be thinned each year.In late June/early July, when fruit is marble-size, thin by picking smallest fruits, leaving 1 or 2 per cluster.

Thin fruit to 1 or 2 per cluster for best quality and

annual bearing.