20 Common Cherry Tree Problems and Diseases (Identification, and How to Treat)

Few things are more disappointing than a cherry tree that struggles. You wait all year for blossom and fruit. Then brown mould, spotted leaves or oozing bark ruins the season.

I have seen many cherry trees recover with the right care. The key is to spot problems early and act at the right time. In this guide, I cover 20 common cherry tree problems in four groups: fungal diseases, bacterial and viral diseases, insect pests, and weather-related problems.

How to Spot Trouble Early

Most cherry problems show clear warning signs. Check your tree every week in spring and summer. It takes only five minutes.

Look for these signals:

• Spots, holes or yellow leaves that drop early
• Brown, collapsing blossoms in spring
• Sticky sap or gum on branches and trunk
• Black swellings on twigs
• Sunken or shrivelled fruit with grey spore tufts or tiny grubs

Keep a simple notebook. Write down the date and the symptom. This helps you match the problem to the right season and treatment.

A quick note on sprays: always read the product label and follow local rules. Your county Extension office can advise on products that are legal and safe in your area.

Fungal Diseases of Cherry Trees (8 Problems)

Fungi cause most cherry diseases. They spread in wet, humid weather and often survive the winter on dead leaves, mummified fruit or cankers. Good sanitation is your first line of defence.

1. Brown Rot

Brown rot is a serious disease of cherries. The Connecticut Agricultural Experiment Station calls it the most common and destructive cherry disease in that state. It is especially severe in wet, humid weather.

The fungus (Monilinia fructicola) attacks in three ways. It causes blossom blight, twig cankers and fruit rot. Penn State Extension describes flowers that collapse and turn brown. Ripening fruit browns and shrivels, covered in tan to grey spore masses.

Sanitation is essential. Remove mummified fruit from the tree and the ground. Prune out dead and cankered twigs and destroy them.

Thin the canopy so air can move through. In wet springs, protective fungicide sprays may be needed at bloom and before harvest. Do not eat rotten fruit.

2. Cherry Leaf Spot

Cherry leaf spot (Blumeriella jaapii) is one of the most serious cherry diseases in the Midwest, according to Ohio State University Extension. It attacks both sweet and sour cherries. It also affects ornamental cherries.

Small purple spots appear on the upper leaf surface in late May and early June. They grow to about a quarter of an inch and turn reddish-brown. The centres may fall out, leaving a “shot-hole” look. Infected leaves turn yellow and drop.

This matters because early leaf loss weakens the tree. Oregon and Washington handbooks note that early defoliation delays cold hardening of flower buds. This can reduce bloom and fruit set for two seasons.

The fungus overwinters in fallen leaves. Rake and destroy leaves in late autumn. West Virginia University Extension adds that the optimum temperature for infection is 63 to 68°F. At those temperatures, only five hours of leaf wetness is enough.

3. Black Knot

Black knot is easy to recognise. Hard, black, warty swellings form on twigs and branches. Penn State Extension says the galls grow larger each year and become very rough. In spring, they are covered with an olive-green, felt-like growth.

The disease is not always harmful at first. The Connecticut station explains that damage becomes serious when a gall completely encircles the branch. The branch then dies beyond the gall. New infections may not show until the following year.

Pruning is the main cure. Cut several inches below the gall and do it before budbreak. Burn or bag the cuttings. Do not leave them near the tree.

Penn State also advises removing wild Prunus trees nearby. They can harbour the fungus. On a trunk or large limb, cut out the gall and about 1 inch of wood around it.

4. Powdery Mildew

Powdery mildew looks like a white or grey dust on young leaves and shoots. Leaves may curl or look distorted. It is more common in areas with warm days and cool, humid nights.

The good news is that it is rarely a big issue in every region. The Connecticut station says it is generally not prevalent on cherry there and would seldom warrant control. In other climates, it can be more troublesome, especially on young trees.

Good airflow is the best prevention. Prune to open the canopy and avoid overhead watering. Avoid heavy nitrogen fertiliser, which pushes soft, susceptible growth.

If it becomes severe, ask your local Extension office about suitable fungicides. Most mature trees tolerate light mildew without serious harm.

5. Leucostoma (Cytospora) Canker

This is a fungal canker that attacks weak or wounded trees. Penn State Extension lists its symptoms as branch dieback and multiple perennial cankers. Gum oozes from the cankers and becomes a blackened crust.

The fungus enters through wounds. Frost cracks, pruning cuts, sunscald and insect damage all give it a way in. Stressed trees are much more at risk.

You cannot cure an old canker with a spray. Prune out infected wood in dry weather, cutting well below the visible damage. Disinfect your tools between cuts.

Prevention is about tree health. Water in drought, avoid trunk wounds and protect the bark from sunscald. A healthy tree resists canker far better.

6. Silver Leaf

Silver leaf gets its name from the metallic, silvery sheen on infected leaves. The fungus (Chondrostereum purpureum) lives inside the wood. Branches may die back one at a time. A dark stain often appears in the wood when you cut a branch.

The fungus spreads by spores that land on fresh pruning wounds. This happens most often in cool, damp weather. That is why timing your pruning is so important.

Prune cherries in dry summer weather rather than in winter. Wounds heal faster in warm, dry conditions. Remove and destroy dead wood promptly.

Some trees recover by themselves, but many do not. If the trunk is affected, the tree may not survive. Keep a close eye on any silvering leaves.

7. Phytophthora Root and Crown Rot

This disease starts underground, so you often see it too late. Water moulds (Phytophthora) attack roots and the crown, especially in wet, poorly drained soil. Michigan State University lists it among the key cherry diseases.

Above ground, you may see wilting, yellow leaves and slow growth. The wilting happens even when soil moisture is good. At the base, the bark can be dark and sunken.

Prevention is far easier than a cure. Plant in well-drained soil, or on a raised mound if your soil is heavy. Never pile mulch against the trunk.

Avoid overwatering, especially in spring. If the tree is already badly affected, replacement may be the only realistic option. Choose a better-drained spot.

8. Armillaria Root Rot

Armillaria root rot is also called honey fungus. It kills roots and the base of the trunk. Trees decline slowly, with thin foliage, small leaves and dieback.

Look for white fungal sheets under the bark at the base. Honey-coloured mushrooms may appear near the trunk in autumn. Black, string-like structures called rhizomorphs can also spread through the soil.

There is no simple cure. Remove badly affected trees, and take out as many roots as possible. Do not replant cherries in the same spot right away.

Keep trees healthy and avoid planting where old stumps remain. Good drainage and avoiding trunk damage help reduce risk.

ALSO READ: 30 Trees That Don’t Lose Their Leaves (With Pictures)

Bacterial and Viral Diseases (4 Problems)

These diseases are harder to treat. Prevention, clean nursery stock and careful pruning matter most.

9. Bacterial Canker

Bacterial canker (Pseudomonas syringae) causes oozing, gummy cankers on branches and trunks. It also causes blossom death and dieback. It often hits young trees in cool, wet springs.

UC IPM explains that the disease is related to tree stress. Poor nutrition, drought, spring freezes and irrigation that wets the tree all play a role. Ring nematodes in the soil can also weaken trees and make them more prone to canker.

Rootstock matters too. In California, Mahaleb is the most tolerant of bacterial canker. Colt is moderately susceptible, and Mazzard is susceptible. UC IPM also notes that spring and summer pruning may help.

Remove infected limbs in dry weather. Disinfect your pruning tools. Avoid wounding trees in autumn and winter when bacteria are active.

10. Crown Gall

Crown gall causes rough, tumour-like growths at the base of the tree or on the roots. The galls are caused by bacteria (Agrobacterium tumefaciens) in the soil. Michigan State University includes it in its list of cherry diseases.

Galls slowly cut off the flow of water and nutrients. Infected trees may look stunted and weak. The problem is often introduced through infected nursery stock.

Buy only healthy, certified trees. Inspect the roots and crown before planting. Reject any plant with swellings.

Avoid wounding the trunk with mowers and trimmers. Wounds are entry points. There is no reliable cure, so remove and replace severely affected trees.

11. Prunus Necrotic Ringspot Virus

This virus causes odd symptoms. Penn State Extension lists delayed leafing on branches or the whole tree. Leaf margins can be wavy and rough. Spots on the leaves die and fall out.

The virus spreads in several ways. It can be transmitted through grafting, seed and pollen. That means infected nursery material is the main risk.

There is no cure for viral diseases in trees. Buy virus-tested stock from a reputable nursery. Avoid grafting from unknown trees.

If your tree is weak but still fruits, you can keep it healthy with good care. Good nutrition and watering reduce the stress it causes.

12. X-Disease

X-disease is a serious disease caused by a phytoplasma, a tiny bacterium-like organism. Michigan State University lists it among the key cherry diseases. It is usually spread by leafhoppers.

Fruit on infected branches is small, pale and misshapen. It often fails to colour properly. Over the years, limbs decline and the tree can die.

Wild chokecherry and other Prunus plants nearby can carry the disease. Remove wild hosts close to your orchard or garden. That lowers the number of infected insects.

There is no cure. Remove infected trees to protect others. Control of leafhoppers can help in orchards.

Insect Pests of Cherry Trees (6 Problems)

Insects damage cherries in many ways. Some chew leaves. Others tunnel inside the fruit. Early detection and good hygiene help enormously.

13. Black Cherry Aphid

Black cherry aphids are small, shiny black insects. They feed in clusters on the youngest shoots. The Connecticut station says they injure young sweet cherry trees by causing leaf curling and growth problems.

Heavy infestations can stunt growth and reduce fruit set the following year. The insects also produce sticky honeydew. Sooty mould then grows on the honeydew, coating leaves and fruit.

Eggs overwinter on the bark. Nymphs hatch when buds open in spring. By June, most aphids move to plants in the mustard family. They return to cherries in autumn.

A dormant oil spray can suffocate overwintering eggs. In spring, insecticidal soap works well if applied before leaves curl. Ladybirds and lacewings also help.

14. Cherry Fruit Fly (Cherry Maggot)

Cherry maggots cause “wormy” fruit. The Connecticut station names two species: the eastern cherry maggot and the black cherry fruit fly. Adults have banded wings and mostly black bodies.

Adults emerge from the soil between late May and July. Females feed for about 10 days, then lay eggs in developing cherries. The maggots tunnel through the fruit for about two weeks. Damaged areas appear as sunken spots.

After feeding, the maggots drop to the soil. They pupate in the top 2 inches and wait for next spring. That is why cleaning up the ground matters.

Hang yellow sticky traps in the tree to detect flies. Pick up fallen fruit. In areas with high pressure, timed sprays or netting may be needed.

15. Spotted Wing Drosophila (SWD)

Spotted wing drosophila is a tiny invasive fruit fly. Adults are only about 2 to 3 millimetres long. Males have a dark spot near each wing tip.

The danger is what it attacks. Washington State University explains that, unlike most vinegar flies, SWD attacks healthy fruit as it ripens. Eggs are laid beneath the skin as the fruit softens and begins to colour.

UC IPM adds that fruit becomes susceptible as soon as its colour begins to change. Populations build quickly because of the fly’s fast life cycle. Larvae cause soft, sunken areas.

Harvest often and do not leave ripe fruit on the tree. Collect fallen fruit and seal it in a clear plastic bag in the sun. Fine insect netting can protect a small tree.

16. Plum Curculio

Plum curculio is a small snout beetle. Adults are dark brown and about a quarter of an inch long. They have humps on their wing covers.

According to the Connecticut station, adults become active about the time trees blossom. They feed on blossoms and young fruit. Females lay eggs in crescent-shaped scars on the fruit skin.

The larvae feed inside and often cause fruit to drop early. Adults overwinter in leaf litter and nearby woods. That makes them hard to avoid entirely.

Clean up fallen fruit and debris. A well-timed spray at shuck split may be needed in orchards. Early monitoring helps you act before damage spreads.

17. Eastern Tent Caterpillar

Eastern tent caterpillars build silken tents in the forks of branches. They leave the tent to feed on leaves. Damage ranges from almost nothing to complete defoliation.

The Connecticut station notes that severe outbreaks happen about every 7 or 8 years. Egg masses on the twigs overwinter and hatch in early spring. The hairy caterpillars mature by late June.

The easiest control is by hand. Prune off small tents early in the morning or evening when the caterpillars are inside. Scrape egg masses from twigs in winter.

For heavy infestations, biological sprays can help when the caterpillars are small. Healthy trees usually recover from one season of defoliation.

18. San Jose Scale

San Jose scale is a tiny sap-sucking insect. The females sit under a circular grey covering, about 1/16 of an inch across. It has a raised centre like a small nipple.

Large infestations can be deadly. The Connecticut station reports that heavy scale populations can cause branch and even tree death. Bark may look rough, grey and encrusted.

Young yellow crawlers appear in June. A second generation may follow in August. The crawlers settle on twigs and suck sap.

Apply dormant oil in late winter to smother overwintering scales. Check twigs closely in spring. Wrapping black tape with a sticky coating around branches can help you see the crawlers.

ALSO READ: 15 Fruit Trees That Can Grow in Pots (With Details)

Weather and Growing Problems (2 Problems)

Not every problem comes from a pest or pathogen. Weather also does serious harm. These issues are often about timing and site choice.

19. Fruit Cracking

Rain on ripening cherries can split the skin. The fruit swells with absorbed water and cracks. Cracked cherries rot quickly, and pests and fungi move in.

It is one of the most frustrating problems for sweet cherry growers. It often happens in the last days before harvest. The damage can affect a large part of the crop.

Variety choice makes a difference. Oregon State University Extension lists Attika, Benton, Lapins and Sweetheart as varieties with more resistance to cracking from rain. Choose them if you live in a wet area.

In a small garden, you can cover the tree with a simple rain shelter. Harvest early if rain is forecast. Avoid heavy irrigation just before harvest.

20. Frost and Winter Injury

Late spring frost can kill open blossoms. Cherries bloom early, which makes them very vulnerable. Even a few degrees below freezing can ruin a crop.

Winter cold can also damage buds and bark. Trees that lose leaves early to disease are at more risk. The Connecticut station warns that trees defoliated year after year are prone to winter injury.

Site selection is your best protection. Avoid low spots where cold air settles. A slope with good air drainage is safer. Choose later-blooming varieties in frost-prone areas.

On cold nights, cover small trees with frost cloth. Wrap young trunks in winter to prevent sunscald and cracks. Healthy, unstressed trees survive cold far better.

ALSO READ: 20 Evergreen Trees That Grow in Shade (With Growing Details)

Cherry Tree Prevention Checklist

Most cherry problems are easier to prevent than to cure. These habits make the biggest difference:

• Choose resistant varieties that suit your climate.
• Plant in full sun and in well-drained soil.
• Prune for airflow, in dry weather.
• Clean up fallen leaves and fruit every autumn.
• Disinfect tools between cuts.
• Water at the base, not over the leaves.
• Buy certified, disease-free trees from a reputable nursery.
• Inspect weekly during spring and summer.

Final Thoughts

Cherry trees can face many problems, but most are manageable. The main rule is simple: good sanitation, good site and good timing. A little attention each week saves you a lot of trouble later.

If you are unsure what is wrong, take a clear photo and a small sample to your local Extension office. Experts there can identify the problem and recommend safe treatments for your area.

I believe every cherry tree deserves a fair chance. With patience and care, yours can give you healthy blossom and sweet fruit for many years.

References

1. The Connecticut Agricultural Experiment Station. Cherry (Prunus) – Plant Pest Handbook. https://portal.ct.gov/caes/home/plant-pest-handbook/pphc/cherry-prunus
2. The Ohio State University Extension (Ohioline). Cherry Leaf Spot. https://ohioline.osu.edu/factsheet/plpath-fru-40
3. Penn State Extension. Ornamental Cherry Diseases. https://extension.psu.edu/ornamental-cherry-diseases
4. University of California Statewide IPM Program. Bacterial Canker – Cherry. https://ipm.ucanr.edu/agriculture/cherry/bacterial-canker/
5. Washington State University (HortSense). Cherry: Spotted Wing Drosophila (SWD). https://hortsense.cahnrs.wsu.edu/fact-sheet/cherry-spotted-wing-drosophila-swd/
6. West Virginia University Extension. Cherry Leaf Spot. https://extension.wvu.edu/lawn-gardening-pests/plant-disease/tree-fruit-disease/cherry-leaf-spot
7. Oregon State University Extension Service. Fruit tree selection. https://extension.oregonstate.edu/gardening/berries-fruit/fruit-tree-selection