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It’s not just humans that enjoy fruit. All the fruits we grow are also considered delicious by a variety of other animals and insects. Furthermore, fruit trees are subject to a range of fungal, bacterial, and viral diseases. See our list of common diseases and pests.

Clockwise: Apple scab, Fireblight, European Apple Sawfly, Sooty Blotch/Flyspeck, Peach Tree Borer.

What this means in practical terms is that your trees will require some time and work to keep them healthy. But while you are pruning and raking and fencing, just remember all the sweet, sun-ripened fruit that’s coming your way!

Basic Preventative Care

While the different species and even the different varieties of fruit tree each have their own particular sensitivities, there are some generalizations that can be made about all fruit trees when it comes to preventative care:

Your trees will need to be protected from wildlife (deer and rodents) and mechanical damage (mowers, weed eaters, etc.).
A tree that is subject to injury, drought, lack of sun, or poor soil will be weakened by these conditions. Weak trees are more susceptible to disease and less able to recover from injury.
Removing organic debris from the growing area will also remove a major disease vector.
Thoughtful annual pruning is essential to maintaining the health of any fruit tree.
Trees want to be looked at! Inspect your trees regularly, especially during the growing season. Early detection of any disease or pest damage will improve your chances of being able to successfully resolve the issue.

Disease-Resistance and Susceptibility

One of the easiest preventative steps is to plant varieties that are disease resistant. When starting an orchard, it is advisable to contact your local university cooperative extension or another local grower to find out what are the most prevalent disease and pest issues in your area. You can then look for varieties that are resistant to diseases you wish to avoid. If a tree has known resistances or susceptibilities, we have listed these on its variety page. Natural disease resistance is an especially important consideration if you are planning on organic cultivation.

Rootstocks

Growing trees on disease-resistant rootstocks will help prevent a range of problems. Although a fireblight-resistant rootstock does not make the whole tree fireblight resistant, it will protect the root system from this disease. Similarly, there are some issues, such as replant disease, that affect only the root system. In short, resistant rootstocks play a huge role in tree health, but they are not the solution to all a grower’s problems.

Diagnosis

The table below is designed to help you spot the most common diseases and pests that affect fruit trees; it’s a Greatest Hits of fruit-tree afflictions. There are plenty of other diseases, but these are the most likely culprits for many problems. Not all symptoms of a disease will appear at the same time, as diseases and insects have their own life-cycles. More information can be found on each disease by clicking on the links.

Tree Type	Symptoms	Disease or Pest
all fruit	chewed or disappeared shoots; bark damage; broken limbs	deer or rodents (mice & voles)
all fruit	white powder-like mold	powdery mildew
all fruit	visible holes or damaged areas in tree bark that ooze gum	any of the borers: American plum borer and dogwood borer, peach tree borer and lesser peach borer
all fruit	scarred, malformed, rotted fruit; crescent-shaped punctures on fruit skin; larvae in fruit	plum curculio
apple and pear	wilted shoots; well-defined areas of burnt-looking, dead foliage or bark; sticky amber ooze	fireblight
apple and pear	cottony masses at the base of leaves; galls on shoots; general decline in tree health	woolly apple aphid
apple	spots on leaves; brown-black spots on fruit	apple scab
apple	red-black spots on leaves; visible spores on undersides of leaves	cedar-apple rust
apple (and sometimes other fruit)	puncture marks on fruit holes in fruit surrounded by waste; larvae in fruit, rotted fruit	codling moth
all stone fruit (cherry, peach, plum, apricot)	brown, rotted bloom; water-soaked, sunken lesions on twigs; brown or grey mold on fruit	brown rot AKA blossom blight
peach (and sometimes other stone fruit)	an area of darkened and sunken bark that expands every year; amber ooze coming from this area	perennial canker
peach	malformed, puckered and “bubbly” leaves that turn red	peach leaf curl
plum	wart-like fungal growth that starts green and matures to black over several seasons	black knot

Chemicals

As mentioned above, your best resources are often other local growers or the local cooperative extension. Many of the chemical products that larger orchards use are not available to home growers, but if you are a backyard grower who just wants a basic fungicide to apply to their peach tree, your local garden supply store should be able to provide plenty of guidance.