Diseases of Cherry Trees: A Gardener’s Guide
Cherry trees are a joy to grow—beautiful blossoms in spring, delicious fruit in summer, and lovely foliage in fall. But like all plants, they can get sick. If you’ve ever noticed strange spots on leaves, weird lumps on branches, or fruit rotting before it ripens, your tree might be dealing with a disease. Let’s talk about some of the most common diseases of cherry trees face and, more importantly, how you can deal with them .
1. Diseases of Cherry Trees: Cherry Leaf Spot
This is one of the most annoying diseases because it sneaks up on you. One day, your tree looks great. The next, it’s dropping leaves like crazy.
What to Look For:
- Tiny reddish-purple spots on leaves that turn brown.
- Leaves turn yellow and fall off way too soon.
- If it’s bad, you’ll see black spots on twigs, too.
Why It Happens:
- A fungus called Blumeriella jaapii loves moist, humid weather.
- Rain spreads the spores, infecting new leaves.
How to Fix It:
- Rake up and destroy fallen leaves—don’t let them rot under the tree!
- Use fungicide sprays like copper in early spring.
- Avoid overhead watering—wet leaves are an invitation for fungus.
2. Diseases of Cherry Trees: Brown Rot
Ever had perfectly good cherries turn into a gross, mushy mess? Brown rot is to blame.
What to Look For:
- Brown, soft spots on cherries that grow fast.
- Blossoms wilt and turn brown in spring.
- Some fruit shrivels up and clings to the tree instead of dropping.
Why It Happens:
- A fungus (Monilinia spp.) loves warm, damp conditions.
- The infection spreads when you leave old, rotted fruit on the tree.
How to Fix It:
- Pick off and throw away infected fruit immediately.
- Prune branches to improve airflow.
- Spray fungicide during bloom and fruiting stages.
3. Diseases of Cherry Trees: Black Knot
This one is hard to miss—it leaves ugly black lumps all over the branches.
What to Look For:
- Hard, swollen black knots on twigs and branches.
- Over time, branches may start dying off.
Why It Happens:
- The Apiosporina morbosa fungus spreads through spores in the air.
- It enters the tree through tiny cuts or wounds.
How to Fix It:
- Cut off infected branches at least 6 inches below the knots.
- Burn or dispose of the pruned branches far away.
- Apply fungicide in early spring before buds open.
4. Diseases of Cherry Trees: Powdery Mildew
Leaves looking like they’ve been sprinkled with flour? Yep, that’s powdery mildew.
What to Look For:
- The leaves, stems, and buds all have a white, powdered coating.
- Leaves may curl or become twisted.
- Affected cherries can have rough, scabby patches.
Why It Happens:
- The fungus Podosphaera clandestina thrives in warm, dry air.
- It spreads fast when airflow is poor.
How to Fix It:
- Spray leaves with a sulfur or baking soda solution.
- Prune dense branches to improve air circulation.
- Water the leaves in the morning so they dry out over the day.
5. Diseases of Cherry Trees: Bacterial Canker
If your tree has oozing sores, it’s time to take action.
What to Look For:
- Dark, sunken sores on bark that ooze sticky gum.
- Small holes in leaves looks like they’ve been shot.
- Branches start wilting and dying, especially in spring.
Why It Happens:
- The Pseudomonas syringae bacteria infects weak or damaged trees.
- Stress from frost, drought, or injury makes it worse.
How to Fix It:
- Prune infected branches on a dry day moisture spreads bacteria.
- Use copper sprays to reduce bacterial spread.
- Water and fertilize your trees properly to keep them healthy.
Final Thoughts
Cherry trees are amazing, but they do need some care to stay healthy. The good news? If you keep an eye on them and act fast when problems show up, you’ll have a good chance of beating these diseases. A little pruning, proper watering, and a few sprays of the right treatment can go a long way. And when your tree rewards you with juicy, sweet cherries, all that effort will be worth it .
References
- Ogawa, J. M., & English, H. (1991). Diseases of Temperate Zone Tree Fruit and Nut Crops. University of California Press.
- Sutton, T. B., & Unrath, S. R. (1984). “Epidemiology and Control of Cherry Leaf Spot.” Plant Disease, 68(3), 195-200.
- USDA Agricultural Research Service. (2023). “Cherry Disease Management Guidelines.
- Cornell University Cooperative Extension. (2023). “Fruit Tree Disease Prevention.”
