- Solving Cherry Problems
- Yellowing leaves and leaf loss reported in tart cherries
- Photo 1. Bacterial canker. Photo credit: A. Jones and E. Lizotte, MSUE
- Photo 2. Cherry leaf spot. Photo credit: A. Jones and E. Lizotte, MSUE
- Photo 3. Sour cherry yellows. Photo credit: A. Jones and E. Lizotte, MSUE
- Photo 4. Green ring mottle. Photo credit: A Jones and E. Lizotte, MSUE
- Photo 5. Copper phytotoxicity. Photo credit: A. Jones and E. Lizotte, MSUE
- Cherry Tree Diseases: Tips On Treating Cherry Diseases
- Cherry Tree Problems
- Treating Cherry Diseases
- Other Diseases of Cherry Trees
- Solving Problems with Yoshino Cherry Trees
Solving Cherry Problems
Cracks In Trunk; Branch Crotches
Too Cold – Oriental cherry trees that are subjected to lower than normal winter temperatures may develop cracks along the trunk on the south or west side. Sometimes these cracks appear where branches meet the trunk. Ornamental cherry trees located in the east above southern New Jersey are at risk.
Leaves Yellow Then Drop
Soil Too Wet/Dry; Or Too Cold. – When leaves on an ornamental cherry tree turn yellow and begin to drop in spring or early summer, it is often because the soil is either too dry or too wet. Sometimes it is due to late cold weather. This problem can be distinguished from a disease because there is no spotting of the leaves prior to their drop. Usually affected trees develop a second set of leaves that are normal.
Plant Parts Skeletonized
Asiatic Garden Beetle – These beetles are velvety chestnut-brown. Nearly 1/2 inch long, they resemble Japanese beetles. They lay their eggs in the soil at the base of the cherry trees. Their larvae (grubs) feed on roots and the bases of young stems. They’re grayish, 3/4 inch long, and curl in a C-shape like Japanese beetle grubs. Adult beetles feed at night, skeletonizing cherry foliage. They hide in the soil during the day. For more information see Controlling Asiatic Garden Beetle.
Holes In Leaves And Flowers
Japanese Beetle – Japanese Beetles converge in droves and skeletonize cherry leaves and destroy their flowers. Their grubs sometimes attack tree roots. Adults are ½-inch long, with shiny metallic green and copper-brown wing covers. Beetle larvae (grubs) are grayish-white, with dark brown heads. Fully grown grubs are plump, 3/4 to 1 inch long, and lie in the soil in a distinctive arc-shaped resting posture. For more information see Controlling Japanese Beetles.
Holes in Trunk
Peach Borer – Adult borers are wasp-like moths. They lay eggs around the base of the trunk in late summer and early fall. These hatch into white, 1 1/4-inch-long caterpillars with brownish heads. They burrow into the trunk as high as a foot above the ground or several inches below the ground. Holes in the trunk near the base of the tree from which brown frass (sawdust) and gum exude are signs that borers are at work. Young cherry trees can be killed during the first season of infestation. For more information see Controlling Borers.
Webbed Nests in Tree Branches
Tent Caterpillars – Tent caterpillars are black and hairy with white stripes and have narrow brown and yellow lines and a row of blue spots along their sides. They pests grow to be about 2 inches long in large silken nests in the forks of tree branches. They feed on tree foliage. Wild cherry trees are natural hosts for these pests. Destroy any derelict wild cherry trees in the area. For more information see Controlling Tent Caterpillars
Small Bumps On Leaves And Twigs
Scale – Scale insects form groups of small bumps or blister-like outgrowths on stems and leaves. About 1/10 inch in diameter, these waxy shells protect the insect feeding beneath. These gray bumps have a raised nipple in the center and are clustered in masses on stems where they join branches or close to growing tips. They cause leaves to turn yellow, and they often secrete honeydew, which covers leaves and encourages sooty mold. For more information see Controlling Scale
Holes in Leaves
Pear Slug – The larvae of sawflies are called pear slugs. They are a slimy, translucent olive-green worms about 1/2 inch long. Wider at the head than at the tail, they resemble a tadpole. They damage ornamental cherry trees at night, skeletonizing their leaves. They typically have 2 generations each season in the north and 3 in the south. They are mostly in the eastern United States.
Red Spots on Leaves; Holes
Leaf Spot – Leaf spot fungi cause red spots on the leaves of cherry trees that rot out, leaving holes in the foliage. Heavily infected leaves turn yellow or brown and fall prematurely. Cool, moist spring weather encourages this disease when new leaves are developing. It is rather prevalent in ornamental cherry trees. Shake out all fallen and diseased leaves from the cherry tree and destroy them. Remove all dead branches in the center of the tree to allow better aeration. Mulching helps prevent the disease from splashing up from the ground and infecting plants. For more information see the file on Controlling Fungal Disease
Yellowing leaves and leaf loss reported in tart cherries
Defoliation has been observed in many tart cherry orchards across the region. The list of potential culprits causing this leaf drop is long, and we are still investigating the cause of defoliation in many blocks.
First, bacterial canker is prevalent in tart cherry blocks with our cool, wet spring. This disease is most problematic in sweet cherries, but under the right conditions, bacterial canker can be present in tart cherries following cold, wet weather during bloom. Leaves that had bacterial canker infections earlier this season are now turning yellow and dropping from the trees. Canker symptoms on tart cherry leaves are characterized by large, brown spots that are circular to somewhat angular. Sometimes these spots coalesce and form large, dead areas on the leaves; leaves with bacterial canker also have a tattered appearance (Photo 1). We are seeing leaf drop from these early bacterial canker infections at this time, particularly in tart cherries.
Photo 1. Bacterial canker. Photo credit: A. Jones and E. Lizotte, MSUE
The next offender on the defoliation list is cherry leaf spot. This disease is notorious for dropping leaves; however, with good spray coverage and timing, leaf loss does not usually occur until sometime after harvest. With the loss of crop, growers may have stretched fungicide spray intervals and there was likely wash off with heavy rains early in the season. This scenario resulted in cherry leaf spot infections in May, and many of these early-infected leaves are now dropping from the tree. Photo 2 is a good example of leaves infected with cherry leaf spot. Be sure to flip over the leaf to look on the underside – the fungus will look white and slightly fuzzy. This characteristic will not be present on leaves with bacterial canker.
Photo 2. Cherry leaf spot. Photo credit: A. Jones and E. Lizotte, MSUE
Cherry yellows is a viral disease that also causes tart cherries to drop their leaves. This classic, leaf-yellowing disease is caused by the prune dwarf virus. Defoliation is happening now and often occurs in waves throughout the season. The severity of leaf drop is temperature dependent at 30 days prior to defoliation, and cold temperatures result in increased development of later symptoms. Leaves that are infected by cherry yellows have a yellow and green mottling that is not in a distinct pattern (Photo 3).
Photo 3. Sour cherry yellows. Photo credit: A. Jones and E. Lizotte, MSUE
Another viral disease that causes defoliation in tart cherry is green ring mottle virus. We do not regularly observe this disease as most of our trees are certified virus-free. Leaves infected with green ring mottle virus are similar to those infected with cherry yellows, except that the green spots within the yellow leaf are in a ring pattern (Photo 4).
Photo 4. Green ring mottle.
Photo credit: A Jones and E. Lizotte, MSUE
The last two potential causes of leaf drop this season are from phytotoxicity, caused by spray applications that are still under investigation. Growers have reported leaf loss after using dodine and copper products. We cannot conclude for certainty that these materials caused the leaf loss as it has not been consistent in all orchards. There may be secondary factors in blocks that caused leaf drop, such as temperature, humidity, slow drying time, fast drying time and other factors. Dodine has not been recommended for sweet cherries because of the potential for phytotoxity, and we have observed phytotoxity in Balatons in past seasons. We suspected that dodine phytotoxity in Balatons is a result of the sweet cherry parentage in this variety. Last season, growers observed phytotoxity in Montmorency, and the common denominator in those blocks appears to be the use of dodine (no photo available at this time). Leaves that are damaged from spray applications will eventually drop from the tree.
Lastly, we have some reports of phytotoxicity from copper products (Photo 5). Many growers that used copper in the 1960s remember the phytotoxity issue in tart cherries with copper use, as copper was one of the recommended fungicides for cherry leaf spot control. More recent data have shown that copper products are particularly effective against cherry leaf spot and provide excellent control at 1.2 lbs of metallic copper. However, the potential from phytotoxicity from copper use remains a concern for many growers, and this year we have evidence that suggests that some copper formulations can cause some leaf loss. But as mentioned above, we have blocks where copper was used and defoliation was a concern while other blocks received the same amount of copper product and resulted in significantly less leaf loss.
Photo 5. Copper phytotoxicity. Photo credit: A. Jones and E. Lizotte, MSUE
Until we further investigate this issue, growers should not abandon the use of copper products, particularly as those blocks that have used copper exclusively this season are some of the cleanest cherry leaf spot orchards in the region. Some of this phytotoxicity may also be related to the amount of lime used in a copper spray – many growers have reduced the lime in the spray tank as it is difficult to use. Reduced amounts of lime may have influenced the phytotoxicity in the copper applications.
Dr. Sundin’s work is funded in part by MSU’s AgBioResearch.
Cherry Tree Diseases: Tips On Treating Cherry Diseases
When a cherry tree looks sick, a wise gardener wastes no time in trying to figure out what is wrong. Many cherry tree diseases get worse if untreated, and some can even prove lethal. Fortunately, it usually isn’t too hard to diagnose the problem. The common cherry tree diseases have recognizable symptoms. Read on to learn more about cherry tree problems and the best methods of treating diseases of cherry trees.
Cherry Tree Problems
Common cherry tree problems include rot, spot and knot diseases. Trees can also get blight, canker and powdery mildew.
Root and crown rot diseases result from a fungus-like organism that is present in most soils. It only infects the tree if the moisture level of the soil is very high, like when the tree grows in standing water.
Symptoms of rot diseases include slowed growth, discolored leaves that wilt quickly in hot weather, dieback and sudden plant death.
This is one of the worst cherry tree diseases. Once a cherry tree has a rot disease, there is no cure. However, rot diseases of cherry trees can generally be prevented by making sure the soil drains well and regulating irrigation.
Treating Cherry Diseases
Treatment is available for most other common cherry tree diseases, like black knot fungus. Recognize black knot by the dark, hard swellings on branches and twigs. The galls grow each year, and branches may die back. Treat it early by cutting off an infected branch at a point below the gall, and applying fungicides three times annually: in spring, and just before flowering and just after.
Fungicide application is also the treatment of choice for brown rot and leaf spot. Shriveled fruit covered with spores indicates brown rot, while purple or brown circles on leaves signal Coccomyces leaf spot.
For brown rot, apply the fungicide when buds emerge and again when the tree is 90 percent in bloom. For leaf spot, apply as leaves emerge in spring.
Other Diseases of Cherry Trees
If your cherry tree suffers drought stress or freeze damage, it may come down with Leucostoma canker. Recognize it by the cankers that often ooze sap. Prune off these limbs at least 4 inches below the diseased wood.
Coryneum blight, or shot hole, causes dark spots on emerging leaves and young twigs. If cherry fruit is infected, it develops reddish bumps. Prune away all diseased parts of the tree. This disease can often be prevented by taking care not to let irrigation water touch the tree leaves. For severe infections, apply copper spray at 50 percent leaf drop.
Prunus avium (Wild Cherry)
Prunus avium, better known as wild cherry, is perhaps one of our most attractive native woodland trees. Wild cherry is often found in old hedgerows and in mixed deciduous woodland, usually at the wood’s edge. According to the Woodland Trust, this species will make a wonderful addition to any wildlife garden. However, when planning your planting do give some thought to space, this beautiful tree can grow up to 25 metres.
Wild cherry will definitely bring a brilliant splash of colour to your garden. Reddish-brown bark, beautiful spring blossom and rich autumn tones are all on offer.
The tree’s light green leaves are oval shaped with a toothed edge. In autumn they’ll give your garden a warm glow, turning a rich red colour before finally dropping. The following spring, usually April, brings showy clusters of pretty white flowers, which attract a whole range of insects. The tree’s fruit – the familiar cherries – are round and are initially yellow-red in colour before ripening to dark red in July. The edible cherries can be bitter in taste and have less flesh than their cultivated relations. However, if you do have plans for their consumption, you will need to be quick! Birds are keen contenders for the wild cherries and can be quick to strip the ripe fruit from the trees. In return for a satisfying meal, a bird will kindly make its contribution to nature by scattering the seeds in its droppings – potential wild cherry trees of the future.
Cherries grow well on any reasonably fertile soil. However, they won’t tolerate waterlogged soil or total shade, preferring a sunny position. Strong winds can quickly destroy the show of spring blossom; so do think carefully about your planting location.
Insects and birds will give you top marks for introducing a wild cherry to your garden. And it’s sure to attract an admiring glance from the neighbours. Beautiful spring blossom, bright summer fruits and warm autumn leaves – what better way to bring a touch of natural beauty to your home.
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Cherries were listed by Governor Hamilton in his 1790 account of the produce grown in Bermuda, so they must have been introduced before this date (Collett, 1987). A mature Surinam Cherry tree is also listed in an inventory of trees taken at Orange Valley, Devonshire in 1840 (Collett, 1987).
Upon arrival in Bermuda, Surinam Cherry became naturalised and began reproducing and spreading from gardens into the surrounding forest. Surinam Cherry spread fairly slowly until 1900 when Starlings arrived in Bermuda. These birds eat the fruit and spread the seeds. The seed in the centre of the fruit is about 1.2 cm (0.5 ״) in diameter which stops the smaller native songbirds from swallowing it. When the island was denuded following the Cedar scale epidemic in the 1940s Surinam Cherry began to dominate tracts of cleared land. Its spread was further accelerated by the introduction of another large songbird, the Kiskadee, in 1957.
Britton noted in 1918 that Surinam Cherry trees were being cut down because they encouraged another invasive species, the Mediterranean Fruit Fly (Ceratitis capitata) which was an agricultural pest on the island at that time. Despite this early intervention, today Surinam Cherry is common in most terrestrial habitats, except where there is salt spray. It is still used in gardens, particularly for hedges.
In the wild, Surinam Cherry grows as a shrub forming dense thickets, but also as a small tree that can reach up to 6 metres (20 ft) tall with a 20 cm (8״) diameter trunk. Surinam Cherry has relatively deep roots so it can tolerate high winds and Bermuda’s sparse summer rain. In Blue Hole Park Surinam Cherry has created an almost monoculture forest. In this area shrubs are closely spaced with small trunks forming a dense thicket that excludes other plants. Surinam Cherry is closely related to the native White Stopper, which is also in the genus Eugenia. Ironically, as the Cherry has thrived the White Stopper has become rare as these species compete for growing space in the under story of the upland forest.
Britton, Nathaniel Lord. 1918. Flora of Bermuda. Charles Scribner’s Sons, New York.
Collett, Jill. 1987. Bermuda Her Plants and Gardens 1609-1850. Macmillan Publishers Ltd. And the Bermuda National Trust.
There are many varieties of the cherry tree; the ornamental/flowering variety which includes species such as the weeping cherry, Kanzan, other Japanese varieties; and the fruiting varieties such as Bing, Stella, Royal Lee, Montmorency and the Meteor. These trees require regular maintenance. However, cherry trees, both the ornamental and fruiting, can be affected by diseases and pests that can affect the otherwise beautiful appearance of the trees as well as their structure and growth. In severe cases, the trees can die. The diseases and pests can also spread to other healthy, trees, thus it is necessary to be able to detect if something is wrong early enough so that you can get help before the situation becomes severe.
Diseases such as powdery mildew, canker, leaf scorch, leaf spot, knot and rot diseases can affect both types of cherry trees. A look at common cherry tree diseases pictures will tell you when something is wrong, so as to get an arborist to look at your trees. Common signs to look out for include, shriveling leaves, dark-colored spots on leaves that are yellowing, trunks, and branches exuding gum in spring and summer, abnormal growth on the bark, white patches on the leaves, and the presence of large numbers of visible pests. For fruiting varieties, you may also notice fruits cracking or falling prematurely.
Treating your cherry trees will help you maintain the aesthetic benefits of your flowering cherry tree varieties, which are known for their beautiful blossoms of different colors as well as their stunning autumn color. If you have planted the fruit-bearing varieties, you also get to enjoy healthy, delicious fruits and other benefits associated with trees.
Solving Problems with Yoshino Cherry Trees
Biggest Problems Growing Yoshino Cherry Trees
Ornamental cherry trees frequently succumb to pests, diseases, and cultural problems. Other types of flowering cherries are also susceptible to this list of complaints.
- Planting in the wrong plant hardiness zone: Yoshino cherries are adapted to growing in USDA plant hardiness zones 5 through 9. When planted in areas outside these limits, the trees are likely to have poor growth and not survive.
- Exposure to salinity: Yoshino cherries do not tolerate salt spray or salinity. While planting near a lake or pond can produce attractive reflections, avoid planting near salt water.
- Planting in poor soil or excessive wind exposure: Cherry trees in general, including Yoshino, need well-drained soil to avoid fungal infection in the root systems, and the blossoms of these trees are easily dislodged by strong winds. Plant on deep, level to slightly sloping ground with protection from wind.
Pests and Diseases Affecting Yoshino Cherry Trees
- Boring Insects: Caterpillars and tree borers, such as peach tree borer, are problematic on these trees. Caterpillars can be controlled with Bacillus thuringiensis, a non-toxic, beneficial bacteria. Peach tree borer can be controlled using beneficial nematodes such as Steinemema carpocapsae and horticultural oils like neem oil.
- Sap-Sucking Insects: Spider mites and aphids suck the running sap from Yoshino cherry trees, causing wilting, discoloration, and falling of leaves. If infestations are small, dislodge the insects with a strong spray of water. For heavy infestations, spray the tree with 2 tablespoons (30 milliliters) of neem oil mixed into a gallon of water or a soap-water solution.
- Bacterial Problems: Twig canker and cherry leaf spot are two bacterial diseases affecting Yoshino cherry trees. Cankers appear as watery lesions on bark, and leaf spot, also called shot hole disease, causes leaf discoloration and holes in the leaves. The best defense is keeping the tree growing vigorously and cutting out infected branches as soon as you see them.
- Fungal Diseases: Various forms of rot, blight, and mildew are common on Yoshino cherry trees. These problems can be hard to control once they have established themselves, making planting in an optimum location, raking up leaf litter, and pruning diseased branches the best methods of prevention.
Yoshino Cherry Trees Have a Short Life-Span
Ornamental cherry trees like Yoshino are short-lived trees, often only surviving for 30 to 40 years. If your tree is ailing and old, it may simply have come to the end of its lifespan.