Ornamental Cherry Trees: Identify and Manage Problems

Select a site that receives full sun or at least 6-8 hours of sunlight each day. 

Ornamental cherry trees grow well in fertile soils with a pH of 6.0 to 7.5. Soil needs to be well-drained. 

Planting Trees and Shrubs

There are numerous species and cultivars of ornamental cherry trees that range in size, growth habit, and width. Select a site that can accommodate the tree's mature size and width. 

Don't crowd trees. Poor air circulation traps humidity and keeps leaves wet for a longer period of time.

Proper pruning and training can help prevent or minimize problems by:

• improving air circulation within the tree, thus reducing the potential for foliar diseases; 
• improving tree strength and inducing branching;
• removing dead or broken branches which may encourage disease/insect problems.
• Refer to our guide to pruning trees. 

If there is less than 1” of rainfall per week, water newly planted trees to maintain even soil moisture. Mulch to hold in moisture and to protect the trunk from lawnmower and weed trimmer damage.

Fertilize trees if a soil test indicates a nutrient deficiency and adjust soil pH if recommended by the soil testing lab. Soil pH affects the availability of nutrients to plants.

Cherries tend to have shorter lives when grown as ornamental trees. Their lifespan is about 20-25 years. 

• Anything that stresses them may encourage insect (especially borers) and disease problems. Stressors include drought, physical damage to the trunk, compacted or poorly drained soil, defoliation, winter damage, poor planting stock, etc.
• Do not apply mulch too deeply. Mulch should be no more than 2-3” deep and keep it 6” away from the base of the trunk to prevent vole damage, borer problems, and trunk diseases. 
• Prune out water sprouts and root suckers.

Gummosis is the oozing of sap from wounds caused by borers, mechanical injury, stress, or cankers. Gummosis caused by disease is distinguishable from insect damage and mechanical injuries because sawdust or pieces of bark are not mixed in the sap, as it would be with insect or mechanical damage. 

Stress or abiotic problems can be broken down into three areas:

• Environmental - Tend to be weather-related, drought, too wet, extreme hot or cold temperatures, climate change are examples.
• Poor planting care and site conditions - Begins from how the tree was planted - was it planted too deeply, are the roots still caged in burlap or a wire basket, is there too much mulch up against the trunk? Is there proper drainage, is the soil compacted, or does the tree receive enough sun?
• Physical damage - trunk damage (typically from deer or voles, lawnmowers, or weed trimmers), damaged or girdled roots, or embedded wire or cords strangling the trunk. 

• Ornamental flowering fruit trees may need protection from deer. Use hardware cloth to loosely enclose the trunks of trees vulnerable to deer feeding. Where deer pressure is heavy, try rotating various commercial repellents. Hanging small cakes of deodorant soap from branches may also be helpful.
• Protect young trees from vole damage by surrounding the lower trunk with hardware cloth, which should extend 2-3 inches below soil level.

Voles

Rabbits

Deer

• Mechanical wounds are entry places for disease, insects, and can slowly kill the tree. Prevention is the best way to avoid this from happening. 
• Protect trees from lawnmower and string trimmer damage. Place a 2-3” layer of mulch in a wide circle around the trunk to eliminate the need for close trimming of unwanted grass. Keep the mulch 6” away from the trunk. 

Black Knot

Black, gnarled swellings along twigs and branches. It is easier to find after trees have lost their leaves in the fall and through the winter. 

Management

Prune out and dispose of infected wood below visible damage.

Various fungal and bacterial diseases (especially Cytospora canker): Enters through insect feeding or lawnmower wounds, frost cracks, or hail damage.

Cankers, Phytophthora, Verticillium wilt, Armillaria root rot: dark or loose bark usually sunken. Fungal growth is sometimes visible under loose bark.

• Cherry shot-hole disease is a "catch-all" phrase referring to the symptom of tiny round holes (about ⅛” in diameter) in leaves of cherry trees. It can occur early in the season and is worse during wet springs. Eventually, leaves turn yellow and fall off the tree prematurely. Read more about cherry shot hole disease.

• Brown rot is a fungal infection that attacks flowering cherry trees, especially the cultivar 'Kwansan', later in spring just as the flowers are starting to fade. 

Peachtree and lesserpeach tree borer

• These are two similar pests that attack different parts of cherry trees.
• Peachtree borer larvae grow into thick-bodied 1-inch-long larvae with brown heads that burrow through the inner bark of cherry, peach, and nectarine trees at or just below the base of the tree. One borer can kill a small tree; two or more may kill larger trees.
• The lesserpeach tree borer adult lays its eggs on the trunks and limbs of peach and nectarine trees, often in or around wounds and cankers caused by the Leucostoma fungus.
• The activities of both borers results in oozing of amber gum (gummosis) from the holes, which often contains sawdust-like insect frass (larval excrement).
• The gum is produced by the tree as a defensive response to the injury.
• When lesserpeach tree borer wounds are found on small branches, they should be cut out and destroyed.

Fall webworm

Eastern tent caterpillars

Preferred host plants are in the Prunus (cherry) family.

White prunicola scale

Plants in the rose family are preferred J. beetle host plants.