Cherry trees are lovely, low-maintenance fruit trees that you can easily grow and harvest in a home garden. Whether you are growing sweet cherries to eat right off the tree or cultivating sour cherry trees for preserves and other culinary ventures, there are a few cherry tree diseases to look out for.
Fortunately, if caught early enough, many cherry tree diseases can be treated, and further damage can be avoided. Read on to find out how to identify, treat, and prevent cherry tree diseases.
1. Silver Leaf
Silver leaf is a fungal infection that attacks the leaves and wood of cherry trees. It enters plants through scratches or wounds on a tree’s branches which are often caused by pruning. Silver leaf can be identified by the appearance of a silvery sheen on the cherry tree leaves, following by dying branches. Upon inspecting, a cut section of dead branches may present dark-stained centers or bracket-shaped fungi.
To treat silver leaf, start by cutting away all the infected areas of your tree. Then, treat pruned branches with an appropriate wound dressing to avoid a resurgence. Also, make sure to check your tree’s surroundings for other infected plants, and if present, prune them too.
It is crucial that you prune your trees at the correct time of year to prevent silver leaf. During late May to July, cherry trees are at their healthiest, whereas the colder and wetter it gets, the more likely they are to contract fungal diseases through open cuts. Always ensure that your shears are clean and sterilized to avoid spreading diseases.
2. Black Knot
Commonly known for attacking cherry and plum trees, black knot is a fungal infection recognizable by distinctive uneven black galls that grow on the branches of infected trees. Although this fungus takes some time to take hold, once it is present, it effectively strangles or girdles new growth and can be fatal to your trees if left untreated.
To treat black knot, remove all the infected areas of the diseased tree during dormancy, pruning roughly ten to twenty centimeters below the infection site. Destroy or burn infected wood to prevent further outbreaks.
If you live in an area prone to the presence of black knot, take care when selecting your own cherry trees, and opt for those that are resistant to the disease. If this is not an option, consider treating your trees with an organic fungicide or lime-sulfur spray. Make sure your pruning tools are always sterilized.
3. Cherry Leaf Spot
Cherry leaf spot is a fungal disease that first presents with purple spots on older cherry tree leaves. This disease is caused by the fungus Blumeriella jaapii and is particularly partial to sour cherries like the Morello tree. If left untreated, it can spread quickly and negatively impact fruit production. Once a severe infestation takes hold, it can become challenging to manage, so it is best to treat cherry leaf spot urgently.
To treat cherry trees infected with cherry leaf spot, start by removing as many infected leaves as possible. Then, spray your trees with an appropriate fungicide. Home remedies made of dish soap, baking soda, and water are also said to be effective in curbing leaf spot.
Healthy trees are less likely to contract fungal infections, so ensure your cherry tree is fed and watered regularly. Together with this, the regular application of fungicide can prevent active new spores from taking hold.
4. Powdery Mildew
Powdery mildew, podosphaera clandestina, is one of the most common cherry tree diseases, causing both fruit and leaf damage. It is a biotrophic fungus that coats cherry trees with a white powdery substance, and in severe cases, can cause leaves to curl, twist, and become brittle. The presence of this fungus can stunt and reduce new growth.
Powdery mildew can be treated with a safe, commercial chemical control like a fungicide. Alternatively, you can opt for a non-chemical control, like a mixture of baking soda and dormant oil, sprayed on your trees bi-monthly. A combination of apple cider vinegar and water is also effective in the battle against powdery mildew.
The best way to prevent powdery mildew is to ensure your trees are planted in healthy growing conditions. Do not overcrowd cherry trees, as they need good air circulation around them. Dispose of decaying plant matter and fallen leaves around their bases. Make sure not to overwater them.
5. Cytospora Canker
Cytospora canker is one of the most destructive common diseases in cherry trees, affecting productivity and killing younger, less established plants. This canker infects the wood of cherry trees, entering through cuts or bark injuries. It presents as a small necrotic spot on a diseased branch, for example, but quickly spreads and collapses interior wood tissue.
The best treatment for Cytospora canker is removal. Cytospora canker can be pruned away, in which case, make sure you prune well below the infection site. It can also be “surgically removed” by cleanly cutting into the bark around the canker margin and gently removing diseased tissue.
Presently, there is no cure for Cytospora canker, so the best prevention is to maintain the vigor and vitality of cherry trees through proper upkeep. As the disease enters plants through breaks and wounds, train young plants early on to avoid branch breaking, and prune established cherry trees regularly to avoid less frequent large cuts.
6. Crown Rot
Crown rot, born from a fungal strain known as Phytophthora, is an aggressive plant menace that infects and deteriorates the roots of cherry trees near the soil line. Cherry trees suffering from crown rot may present as in noticeable decline, but you will only know for sure when you inspect your tree’s roots. If the layer of tissue behind your tree’s crown bark is brown or orange rather than green, rot is more than likely the culprit.
Unfortunately, there is no way to get rid of crown rot once it has set in because it is hard to detect, and it is usually too late to prevent once it is identified. If not too severe, you can try to recover your plant by removing the soil around the crown and drying it out. However, it is best to destroy plants suffering from this infection, as it spreads quickly.
Crown rot is usually caused by excessive watering and soggy soil. To prevent crown rot, plant your cherry trees in well-draining soil, and err on the side of less frequent watering. Fungicide treatment can be beneficial but is not always effective against this disease.
7. Crown Gall
Crown gall is the cancer of cherry tree diseases. It is caused by bacteria absorbed into a cherry tree’s DNA, creating tumor cells that start in the roots and eventually spread throughout the entire tree. These tumors are usually white, brown, or tan, and if not managed, can significantly damage or kill crops.
To treat crown gall, you will need to use a chemical control substance sprayed across diseased areas and infected branches. This may not cure it, but it will prevent its spread. Exposing and removing tumors can also be an effective means of healing your cherry tree.
Crown gall thrives in warm temperatures and wet environments. To prevent crown gall, try to upkeep the health of your trees by keeping their crowns dry and planting them in well-draining soil. Try to avoid plant wounding or breakage too.
8. Necrotic Ringspot
This disease, caused by bromoviridae ilarvirus, is hazardous to cherry trees in particular. It starts with yellowing and browning on the undersides of leaves that are also frequently holey and necrotic. From there, it can quickly spread to twigs, leaf buds, and branches, stunting a cherry tree’s growth and preventing a successful fruit yield.
You can try to treat necrotic ringspot by pruning away diseased plant matter and applying fungicide, but it may not always be effective. It is best to removed diseased trees to prevent the spread of this virus.
Necrotic ringspot spread through pollen, seeds, wind, and wood grafting and can be challenging to prevent. When choosing cherry trees, it is best to select disease-resistant cultivars where possible. Destroy any plants in your garden that may be infected with necrotic ringspot to avoid the virus getting out of hand.
9. Brown Rot
Blossoms and leaves that brown and wilt but do not drop may indicate brown rot. This cherry tree disease spreads quickly from flowers to twigs, becoming cankerous and stunting the growth and yield of cherry fruit. Brown spores may also be present on infected branches, leaves, and fruit. A healthy cherry tree can turn into an infected cherry tree in a matter of days.
Brown rot is difficult to treat once it has set in. Start by pruning away diseased branches and leaves with sterilized pruning tools. Infected plant matter should be buried or burned to prevent further spreading of the fungus. Pruning will also thin out your cherry tree, allowing for better airflow. For severe infections, you can use a safe organic fungicide.
The best prevention for brown rot is a clean growing environment with good airflow and low moisture. Regularly prune and harvest your cherry trees so that shriveled fruit does not stay hanging on their branches. Pick up and remove plant debris from around the base of the plant. This creates a growing area less conducive to fungal spores.
10. Cherry X-Disease (Cherry Buckskin Disease)
Cherry x-disease is a cherry tree disease transmitted via insects, like leafhoppers, that transfer pathogenic phytoplasma from wild plants to domestic orchards or gardens. Infected cherry trees may bear small, pale fruit with leathery skin and leaves with bronzed complexions. This pathogen is fatal to cherry trees.
In less severe cases of x-disease, you can prune away diseased leaves and branches, burying or burning them to prevent further spreading of the pathogen. While this may stop the spread, it will not cure the infected tree, so it is advisable to remove and destroy it before it causes further damage to your crop
The best way to prevent x-disease is to remove plants that host the insects that spread it. Remove weeds in your cherry tree’s environment, and if possible, introduce beneficial insects that prey on leafhoppers. If you feel your trees are at risk, treat them with safe pesticides.
Final Word On Cherry Tree Diseases
Cherry trees are a treat in the garden, and for that reason, you want to keep them as healthy and happy as possible. Indeed, diseased trees are less likely to produce healthy fruit, so where possible, put preventative measures in place to protect against cherry tree diseases.
Disease prevention is only one part of the care your cherry trees need. Keep reading our guides and resources for growing healthy, productive cherry trees.