Trees with red apples in an orchard

Identifying Fruit Tree Diseases

We’ve received a number of calls lately from clients wondering what to do about the moldy peaches and other signs of fruit tree diseases they’re seeing. Below are some tips for identifying fruit tree diseases, as well as pictures of common problems.

Firstly, it’s important to know that most fruit trees are susceptible to some common diseases. Growing fruit trees requires either some tolerance for imperfections or a willingness to take on a high maintenance treatment program. It’s possible to manage diseases organically, but either way you’ll likely need to treat the trees yourself or have them treated.

When checking your trees for disease, you want to inspect not only the fruit, but the leaves and bark as well. Keep in mind that several diseases show similar symptoms. You may need a professional to help you properly identify and treat your trees’ ailments.

2 peaches with brown rot on a branch
Brown Rot On Peaches



Brown Rot is a minor fungal disease mostly seen on peach and cherry trees, but apricot, nectarine, and plum trees are also susceptible. It is relatively easy to identify and treat.





Apples with Scab
Apple Scab


Apple Scab is a very problematic fungal disease in New England. Scab also affects some pear and peach trees. Read more about Apple Scab on U Mass Extension’s Tree Fruit Management Guide.



apple tree leaf showing small yellow spots from cedar-apple rust
Cedar-Apple Rust


Small, yellow-red-brown spots on the leaves of apple and crabapple trees may indicate Cedar-Apple Rust. This fungal disease can lead to defoliation and increased susceptibility to winter injury.





Leaves show signs of peach leaf curl
Peach Leaf Curl



Peach trees aren’t the only ones affected by Peach Leaf Curl. It also occurs in nectarine, plum and apricot trees. In addition to curling leaf edges you may find discoloration or spots on the leaves.




Curled pear tree leaves indicating fire blight
Fire Blight on a Pear Tree


Watch out for Fire Blight especially in pear and quince trees. Apple and crabapple trees are also susceptible to this bacterial disease. Blossoms will indicate the first signs of Fire Blight, followed by leaves; eventually Fire Blight can kill the entire tree.



If you’re seeing mold or other interesting things sprouting from the leaves and fruit of your fruit trees, give us a call and we’ll help you take care of it. 


PS: Stay tuned for a follow-up post on getting the most out of your home fruit gardening, including a plant list of disease-resistant varieties and tips on growing fruit organically.


Additional sources: Stark Bro’s Nurseries and Orchards, Gardening KnowHow, and SF Gate