15 Fruit Tree Diseases to Quickly Identify and Get Rid Of

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.

apple tree  branches with black rot
Diseased branches with black rot removed from my young apple trees.

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. The “black rot” can be seen on diseased wood, and the spots show up in the leaves and on the fruit.

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.

This led me to discovering that my trees, unfortunately, had black rot. In this post, I’ll tell you more about this frustrating disease, as well as steps you can take to prevent this and other diseases that commonly affect orchards of all kinds.

What Are the Common Diseases for Fruit Trees?

Tree fruits are an important part of the human diet, providing essential nutrients and vitamins. However, fruit trees are susceptible to a variety of diseases, which can cause significant damage to crops.

Here are some of the most common diseases. Knowing how to identify and treat them can make a world of difference!

Black Rot

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.

diseased apple tree trunk with black rot
diseased apple tree trunk with black rot

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.

Peach Scab

Peach scab is a type of fungal infection that affects fruit trees in the genus Prunus. It is characterized by dark, raised spots on the skin of the fruit. The fungus that causes peach scab lives in the soil and can overwinter on infected tree debris.

When the weather is warm and wet, the fungus produces spores that are spread by wind and rain to new trees. Once the spores land on a tree, they Penetrate the fruit through wounds or natural openings.

Treatment for peach scab typically involves applying a fungicide to the tree early in the growing season, before the spores have a chance to infect the fruit.

Preventative measures include removing infected fruit from the ground and pruning away any infected tissue on the tree.

Apple Scab

Apple scab is a fungal disease that affects a wide variety of fruit trees, including apples, pears, and cherries. The fungus responsible for causing apple scab is called Venturia inaequalis, and it thrives in warm, wet conditions.

This fungus attacks the leaves and fruit of trees, causing them to become blackened and distorted. In severe cases,apple scab can cause the leaves of a tree to fall off prematurely.fruit trees.

The fungus responsible for causing apple scab is called Venturia inaequalis, and it thrives in warm, wet conditions. This fungus attacks the leaves and fruit of trees, causing them to become blackened and distorted. In severe cases,apple scab can cause the leaves of a tree to fall off prematurely.

Apple scab can be treated with a number of different fungicides, but the most effective way to prevent the disease is to maintain good hygiene practices in the garden, such as pruning infected leaves and removing fallen leaves from around the base of trees.

In addition, reducing crown density will help to improve air circulation around the tree, which will help to prevent the build-up of moisture that allows the fungus to thrive.

Black Knot

Black knot is a fungal disease that affects several species of fruit trees, including plum, cherry, and apricot. The fungus causes black, swollen knots to form on the branches of the tree.

Over time, these knots can grow to be several inches long and may eventually girdle the branch, causing it to die.

Black knot is most commonly spread by pruning tools or during bud break, when the fungus is released from infected dormant buds. Treatment typically involves applying a fungicide to the affected branches in early spring.

However, the best way to prevent black knot is to remove and destroy any infected branches as soon as they are discovered.

Cherry and Plum Leaf Spot

Cherry and plum leaf spot is a fungal disease that can affect several different species of fruit trees. The most common symptoms of the disease are small, black spots on the leaves of the affected tree.

The disease can also cause the leaves to turn yellow and drop off prematurely. In severe cases, the fungus can infect the fruit of the tree, causing it to rot.

Cherry and plum leaf spot is most commonly caused by overwatering or excessively moist conditions. The fungus thrives in wet, humid environments and can quickly spread from one tree to another.

To treat cherry and plum leaf spots, it is important to remove all infected leaves from the tree. The tree should also be given plenty of ventilation to allow the leaves to dry quickly after watering. In some cases, fungicides may also be necessary to control the spread of the disease.

To prevent cherry and plum leaf spot, it is important to water trees only when necessary and to avoid overcrowding them in gardens or nurseries.

Crown Gall

Crown gall is a plant disease that affects various species of fruit trees, including apples, peaches, and cherries.

The disease is caused by a bacterium called Agrobacterium tumefaciens, which infects the tree through wounds in the bark. The bacterium that causes the tree to produce abnormal growths, or galls, on the trunk and branches.

These galls can eventually kill the tree if left untreated. Crown gall can be treated with chemical pesticides, but the best way to prevent the disease is to avoid wounding the tree in the first place.

Bacterial Leaf Spot

Bacterial leaf spot is a type of plant disease that can affect fruit trees. The bacteria that cause this disease can live in the soil or on the surface of the tree’s leaves. They may also be spread by insects or by contact with contaminated pruning equipment.

Symptoms of bacterial leaf spot include small, dark spots on the leaves of the affected tree. The spots may eventually turn yellow or brown and may fall out, leaving holes in the leaves. In severe cases, the entire leaf may turn brown and die.

Bacterial leaf spot is most commonly seen on peaches, nectarines, and plums, but can also affect other types of fruit trees.

To prevent this disease, it is important to plant disease-resistant trees and to avoid handling them when they are wet. If your tree does become infected, you can treat it with a copper-based fungicide.

Crown Root Rot

Crown root rot is a serious disease that can affect fruit trees of all types. The disease is caused by a soil-borne fungus, and it can quickly kill tree roots, leading to dieback and eventually death.

Crown root rot is most often found in areas with heavy clay soils, and it is especially common in wet or poorly drained areas. Treatment for the disease is difficult, and often involves the removal of affected roots and trees.

However, there are some preventive measures that can be taken to reduce the risk of crown root rot. These include planting trees in well-drained soil, avoiding compaction of the soil around tree roots, and using mulch to help promote drainage.

Phytophthora Root Rot

Phytophthora root rot is a disease that affects fruit trees. It is caused by a fungus-like organism called Phytophthora. This organism lives in the soil and attacks the roots of the tree, causing the roots to rot.

The symptoms of this disease include yellowing leaves, stunted growth, and dieback of the branches. The tree may also produce fewer and smaller fruits. Phytophthora root rot can be treated with fungicides, but it is difficult to control.

The best way to prevent this disease is to plant trees in well-drained soil and to avoid overhead watering.

Fire Blight

Fire blight is a serious bacterial disease that affects fruit trees, especially those in the Rosaceae family. The bacteria, Erwinia amylovora, infects the flowers, leaves, and fruit of the tree, causing them to blacken and curl.

In severe cases, the entire tree can be killed. Fire blight is most commonly seen in apples and pears, but can also affect other trees such as crabapples, quince, and mountain ash. The bacteria are spread by insects or through rain splashing on infected plant parts.

Once a tree is infected, there is no cure. Treatment involves pruning away affected branches and destroying them. To prevent fire blight, growers can use disease-resistant varieties of trees and spray their trees with a Streptomycin-based solution before bloom.

Flyspeck

Flyspeck is a type of fungus that affects fruit trees, such as apples and pears. The fungus grows on the surface of the fruit, causing small black spots to appear. The flyspecks can vary in size, but they are typically around 1-2mm in diameter.

If left untreated, the fungus can spread to other parts of the tree and affect the quality of the fruit. The flyspecks themselves are not harmful to humans, but they can make the fruit less attractive and reduce its shelf life.

There are a few different ways to treat flyspeck. One option is to remove the affected fruit from the tree and destroy it. This will help to prevent the fungus from spreading.

Another option is to use a fungicide, which will kill the fungus and prevent it from causing further damage. Finally, you can also prune out any infected branches, as this will also help to stop the spread of the fungus.

To prevent flyspeck from occurring in the first place, it is important to maintain good hygiene in your garden.

This means regularly cleaning up fallen leaves and fruit, as well as pruning any dead or dying branches. You should also avoid using too much fertilizer, as this can encourage the growth of fungi.

If you do notice any flyspecks on your fruit trees, be sure to treat them as soon as possible to prevent further damage.

Sooty Blotch

Sooty blotch is a fungal disease that affects many types of fruit trees, including apples, pears, and cherries.

The fungus causing sooty blotch, called Scoriaspeminutea minima, produces dark brown or black spots on the surface of the fruit.

These spots are most often found on the upper surface of the fruit, where they may coalesce to form large blotches. The fungus can also affect the leaves of the tree, causing them to turn yellow or brown.

Sooty blotch is most commonly seen in humid weather conditions. The fungus thrives in warm, moist environments and can spread rapidly in these conditions.

Treatment for sooty blotch generally involves the use of fungicides. These chemicals can be applied to the tree trunk and branches to kill the fungus and prevent it from spreading.

In some cases, pruning affected branches may also be necessary. To prevent sooty blotch from occurring, it is important to maintain good hygiene in the garden and to avoid overhead watering of trees.

Cedar Apple Rust

Cedar Apple Rust is a type of plant disease that affects fruit trees. It is caused by a fungus that lives on cedar trees. The fungus attacking causes orange spots to form on the apples. If left untreated, the disease will eventually kill the tree.

To prevent Cedar Apple Rust, it is important to remove all infected leaves from the ground around the tree. The leaves should be bagged and disposed of properly. It is also important to prune infected branches and spray the tree with a fungicide.

Brown Rot

Brown rot is a type of fungal disease that affects fruit trees. The most common species of trees affected by brown rot are apple, pear, and peach trees. The fungus causing brown rot is called Monilinia fructicola.

apricot covered in brown rot
apricot covered in brown rot

Brown rot occurs when the fungus infects the blossom end of the fruit. The fruit will then turn brown and rot away from the blossom end. The affected fruit will eventually fall off the tree.

Brown rot can also affect the twigs and leaves of the tree.

To treat brown rot, remove all affected fruit, leaves, and twigs from the tree. Destroy them so that they cannot spread the disease further. Apply a fungicide to the tree to help prevent brown rot from occurring.

Bacterial Canker

Bacterial canker is a serious disease that affects several species of fruit trees, including apples, cherries, and peaches. The bacteria that cause canker are spread by water, wind, and insects, and they can infect trees through wounds in the bark.

Once a tree is infected, the bacteria can quickly spread through the sapwood, causing cancerous lesions to form on the branches and trunk. The lesions eventually kill the tissue surrounding them, leading to dieback and defoliation.

Treatment for bacterial canker generally involves pruning away infected branches and applying copper-based fungicides to the wound site. However, the best way to prevent this disease is to plant disease-resistant varieties of trees and to avoid wounding the bark during pruning or other cultural practices.

Peach Leaf Curl

Peach leaf curl is a disease that affects fruit trees in the peach family. It is caused by a fungus called Taphrina deformans, which overwinters in infected leaves that have fallen to the ground.

In the spring, the fungus produces spores that are spread by rain or wind to new leaves, causing them to deform and curl. The disease can also affect fruit, causing it to become mottled and distorted. Left untreated, peach leaf curl can severely damage fruit trees and reduce their yield.

There are several things you can do to prevent peach leaf curl, including planting resistant varieties of peach trees and pruning diseased leaves from the tree. If your tree does become infected, you can treat it with a fungicide.

Be sure to follow the directions on the label carefully, as Peach leaf curl is difficult to control once it gets established. With proper care, you can keep your peach trees healthy and free of this damaging disease.

How Do You Prevent Fruit Tree Disease?

Fortunately, there are a number of things you can do to prevent these diseases and keep your trees healthy.

One of the most important things you can do is to maintain proper tree care. This includes watering your trees regularly, pruning diseased branches, and keeping the area around your trees free from debris.

In addition, it’s important to choose disease-resistant varieties of fruit trees whenever possible. If you do notice signs of disease, be sure to contact a certified arborist or other tree care professional for help in diagnosing and treating the problem.

What is the Best Fungicide for Fruit Trees?

There are a variety of different fungicides available on the market, and it can be difficult to choose the right one for your fruit trees. However, there are a few factors that you should consider when making your decision.

First, consider the type of fruit tree that you have. Different trees are susceptible to different types of fungus, so it is important to choose a fungicide that is specifically designed to target the type of fungus that is affecting your tree.

Second, consider the size of your tree. If you have a large tree, you will need a more concentrated fungicide in order to be effective.

Finally, consider the time of year. Some fungicides are only effective during certain times of the year, so be sure to check the label carefully before making your purchase.

Final Thoughts

By familiarizing yourself with the most common fruit tree diseases, you can quickly and easily identify them in your own garden.

With this knowledge, you’ll be better equipped to take action and get rid of any diseases before they have a chance to do too much damage.

Consider implementing some of these tips today and enjoy a healthy, thriving fruit orchard for years to come!

15 thoughts on “15 Fruit Tree Diseases to Quickly Identify and Get Rid Of”

  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?

    Reply
  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

    Reply
  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-.

    Reply
  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.

    Reply
  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……. 😉

    Reply
  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.

    Reply
  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. 🙂

    Reply
  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!

    Reply

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