Have a cherry tree growing in your backyard? Perhaps it’s in good health, or maybe you’ve recently found out that something was growing on it- and it doesn’t look good. Like any other plant out there, cherry trees are most susceptible to diseases caused by a multitude of factors in the environment, from insects to weather.
However, it’s a matter of identifying them and figuring out how to treat and otherwise prevent them from ruining all of your hard work in planting cherry trees. In this article, we have a list of possible cherry tree diseases, as well as tips on how to prevent them from happening. Let’s get to them!
Black Knot
Often affecting branches and twigs, this type of fungal infection is commonly found in cherry and plum trees throughout North America. The disease consists of small, dark-colored swellings that eventually burst when they get bigger. Over time, these swellings also grow into elongated galls that can reach up to 12 inches long, hence their “knot-like” appearance.
Black knot occurs during wet seasons such as the spring, a time when fungi tend to cultivate. Visible symptoms from this disease usually show up about six to twelve months later, but by then the tree is dying, or already dead.
How to Treat and Prevent
- To prevent black knot from happening in the first place, make sure that your cherry tree is properly fertilized.
- If your cherry tree is already infected with the fungus, then take steps to prune any branches and twigs during the fall and winter seasons and sanitize those pruned areas afterwards with bleach and winter to slow fungal growth.
- When spring comes around, treat the tree with fungicide.
Brown Rot
Literally as it sounds, brown rot is another type of fungal disease which affects the fruit, blossoms, and even branches of the tree. Symptoms of this disease include fruit rot and even total wipe out of an entire fruit tree; usually, you can see brown mold eating away at the fruit. Even worse, the disease can spread to uninfected parts of the tree through spores, which latch on and create more brown rot.
How to Treat and Prevent
- For just about any plant disease, it starts by removing any infected areas of the tree, whether cutting down the branches or getting rid of the spoiled fruit.
- Start fungicide treatment as soon as spring season hits, in order to take advantage of the warmer weather before wet conditions hit.
- Also treat for any potential insects, which might come and eat through the fruit, increasing the chances of fungi to enter and multiply.
- On the other hand, prevention is simple, as it’s a matter of picking fruit as soon as they are ripe and cleaning, even burning, affected branches and fruit to make sure that they don’t spread to the rest of the tree.
Cherry Leaf Spot
This particular fungal disease attacks the leaves of the cherry tree, as well as the stems and fruit themselves. It occurs especially in the spring as soon as the weather warms up and gets potentially humid (a breeding ground for many types of fungi to grow in).
The cherry leaf spot leaves small, purple to brown spots on the edges of the leaves before growing bigger and falling out, leaving holes in them. Over time, it weakens the tree, which might be more susceptible to other plant diseases during the winter, as well as preventing the cherries from properly maturing.
How to Treat and Prevent
- Start early in the spring by checking a few samples of tree leaves for signs of spotting.
- During wet and humid weather, check the bottom of the leaves for any hint of spore growth.
- Also treat for any potential insects, which might come and eat through the fruit, increasing the chances of fungi to enter and multiply.
- Once you diagnose and confirm that the cherry tree has leaf spots, go ahead and apply fungicide regularly, from seven to ten days, as well as after harvest season to ensure that the cherry tree is fungus-free.
Leucostoma Canker
Also known as simply “bacterial canker,” this particular disease not only affects cherry trees, but also other fruit trees like that of plums, apricots, and peaches.
Usually, leucostoma canker creates sunken, gummy-like abrasions on tree trunks and twigs. When the weather gets warmer in the springtime, a sour-smelling sap might ooze out from the tree trunk, and eventually the tree might die.
How to Treat and Prevent
- The best way to go about getting rid of cankers is not by pruning it during the spring or the fall when they tend to be the most active.
- Prune any dying or already dead branches and brush the bark with a latex paint-water solution to prevent any temperature-induced fluctuations from ruining the bark.
- Using copper fungicide on young trees, as well as affected ones, will help kill off the cankers and hopefully restore order to your cherry tree.
Powdery Mildew
Powdery mildew is a serious fungal disease in which it attacks leaves and twigs. It forms white, felt-like patches on the targeted areas, which over time causes the leaves to curl, become thin and weak, and eventually drop prematurely. Not only does it look unpleasant to the eye, but it also severely affects the growth of the tree’s assets by stunting them.
How to Treat and Prevent
- Treating the powdery mildew with fungicide is the best way to go about it.
- Begin applying the solution to the leaves and tree itself at the start of petal fall or shuck split; continue to do so in interval every seven to ten daysuntil harvest time arrives.
- Pruning regularly and maintaining the tree will also help prevent future mildew from growing.
*Bonus!* Silver Leaf
A fungal disease that’s caused by open wounds from excessive pruning, silver leaf affects leaves and branches, often seen as a silvery surface on the infected areas. The toxins from this fungus spread into the leaves, and sometimes can even kill branches or complete trees themselves. It especially occurs during the summer.
It’s also important to be careful not to misdiagnose or easily dismiss it, since silver leaf often times is confused with other silver-like symptoms that result from cold and drought in the winter, which are non-diseased factors.
How to Treat and Prevent
- Choose to prune in the summer, since other seasons like fall and winter are when fungi produce their spores.
- Pruning in the summer, then, will allow for developing abrasions caused by the fungi to heal faster.
- Additionally, you can paint over the wounds as means to seal and prevent them from getting worse. Of course, get rid of any infected or dead twigs, leaves, or branches on a regular basis.
Conclusion
While it’s true that there are so many possible cherry tree diseases out there, it’s important to know that it doesn’t necessarily mean the end for your precious tree. By researching and taking the steps to prevent and tree the disease, you’ll have a healthy, growing tree that will yield you a good amount of cherries!
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Hi Shary, I have a cherry tree which seems to have had brown rot for a number of years. Your advice says to trim back infected branches & leaves however it looks like the main trunk is infected. Any suggestions, we think the tree is about 30yrs old and so don’t want to cut it down. Thanks
Hi John,
It’s sad to hear that from you. As I mentioned in the article, besides trimming infected branches & leaves, you should start fungicide treatment as soon as spring season hits. I hope this could help.
Have a great day!