Fruit Tree Diseases. Black Rot and Frogeye Leafspot.


A few weeks ago (late Feb.) I pruned our fruit trees. Drastically. They’re still young, so the branches were easy to remove using loppers, but now they look like nothing more than a tall stick in the ground.

It made me sad to cut so many of the branches away. It feels like such a setback. But if I am to save my fruit trees, which I really hope I can do, it was a necessary step.




Black Rot
Diseased branches removed from my young apple trees.


The Problem

Last summer I noticed something peculiar on my fruit trees. The leaves had developed dark round spots on them, there were black patches in the bark and even places where the branches were bending and gnarled in unnatural ways. The fruit I did get from my apple trees had rotten spots on them even before they finished ripening.

I looked up the symptoms and diagnosed the issue. I’m pretty sure this is a fungus called Black Rot, accompanied by Frogeye Leafspot {link to more information}. The “black rot” can be seen on diseased wood, and the spots show up in the leaves and on the fruit.



Diseased trunk
Diseased apple tree trunk.

As I went from fruit tree to fruit tree examining the dormant branches, I was almost sick to my stomach at what I discovered. Almost every one of my fruit trees was affected.

Two apple trees. Three peach trees. And a plum.

Only the little Montmorency Cherry which I put in last year shows no sign of disease.

The Solution (hopefully)

Black Rot is spread by fungal spores which survive in infected bark and mummified fruits. The recommended method of control is to prune all dead and diseased wood, and either burn that wood or remove it from the property so the spores don’t spread. Spotted leaves which fall from the tree should also be gathered and disposed of properly.

I went around and cut every single branch that had any sign of the disease. The only thing I couldn’t remove was the fungus on the trunk of the tree. I’ll have to research organic fungicides to help control the problem.

Important pruning hygiene tip: I believe I spread the disease from tree to tree when I did my pruning. I’ve since read that you should dip your pruning sheers or loppers in a bleach solution after pruning diseased wood, or after pruning each tree.

I can’t help but wonder if the fungus originated in the wood chips we used to mulch around the trees with. Could I have used diseased wood chips, which splashed fungal spores onto my trees with the rain? I’ll probably stick to pine needles around the trees from now on.

I’m really, really hoping my fruit trees can be saved and I won’t have to uproot and replace them. Fruit trees can be quite an investment.

Have you ever experienced fruit tree diseases? Any advice on how I can eradicate Black Rot?

15 thoughts on “Fruit Tree Diseases. Black Rot and Frogeye Leafspot.”

  1. My plum tree has black rot, but it is still providing numerous amounts of plums, what I want to know is will this black rot make the plums uneatable?

  2. Kendra,
    So sorry to hear about your trees! We put so much into them and then a disease can wipe them out. I had problems with my beautiful peach trees that caused all the fruit to get moldy. What helped was contacting my county extension office. I sent them photos and they did a lot of research for me. They even offered to test the fruit in a lab to be sure. I would contact them again if I have other problems.
    Best of luck with it! I hope you let us know later in the season if the pruning helped.
    Katie @ Katie’s Farm

  3. Use the wood ash from your wood stove to spread *around* the trees. Be sure to NOT get the ash on the tree trunk/bark. Got this tip from Laura Ingalls Wilder -smile-.

  4. We too have been infested with the stinkhorn fungus in our garden. We think it came in on purchased mulch. They killed all the plants that were in the raised bed so we dug out much of the soil and then have encased what remains in black plastic to try to eradicate it.

  5. Okay.
    I hit “summit” too soon. My above comment is positively incoherent. I’ve finally given up on the trees (not financially given up)
    It does require good sanitation (not It dies)
    Now back to vacuuming my stairs……. 😉

  6. Kendra –
    I’ve cut fruit trees down almost to ground level and within 2 -3 years the trees were producing again.
    It’s only a temporary set back 🙂

    Your trees may need a better spray program.
    Google “Bordeaux Mixture”. It’s pretty straight forward fungicidal spray that has been used for well over 100 years. The recipe is easy to make up, but caution must be use when temperatures are over 85F.

    Fire Blight can be an on going problem. I’ve been fighting it for 25 years.
    It dies require good sanitation but also some Streptomycin spray.

    And just so you know, some root stocks will have more trouble with rots than other types of root stock. And many dwarfing root stocks have little to no resistance against Fire Blight. With 3 three in my small orchard I’ve financially given up and will cutting them down this year. I guess you have to pick your battles and know when you’re whipped 😉

    Also it might be a good idea to remove the mulch if you have it around the base of the trees.

  7. Its extremely hard to get rid of black knot or black scat disease. I personally never heard it been called black rot, as rot is black so can be misleading. Prune out the diseased areas 8″ BELOW the rot and sterilize between cuts. DO NOT prune it out in the spring as this is when the spores are the most active. Increase air flow in the tree. and dont plant cherries and plums in the city where it runs rampant. I also have never seen it on apples or peaches. only plum and cherry. Perhaps you are seeing Fire Blight which will attack apples, and is also black looking. 🙂

  8. We’ve had problems with bringing different fungi into our garden through wood chip mulch. From now on we’ll be using straw mulch to try and keep from spreading anything new…but now we have a horrible infestation of Elegant Stinkhorn Mushrooms (google it, they’re awful!) that we’re trying to figure out how to eradicate with little luck so far. Good luck with your trees! I hope they make it!


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