We recently purchased a home that has two large sycamore trees in the back yard. the trees leafed out beautifully this spring, but now they are losing many of their leaves. do you know what would cause this?
The sycamore tree (Platanus occidentalis) is a large and beautiful native tree that is unfortunately subject to several disease and insect problems. The most important of these is sycamore anthracnose, which causes trees to lose many of their leaves during the summer months.
By late summer, some trees will have lost 75 percent or more of their leaves. The disease can spread rapidly during periods of cool wet weather. I expect that this is your problem, and given that we had a very wet spring, the disease will be worse than normal this year. The good news is that it rarely kills trees. Most sycamore trees will carry on through the fall and winter, robustly leaf out again the following spring, and then start the cycle of leaf drop all over again the following summer. The trees are very resilient. Most nurseries and landscapers have stopped selling the sycamore trees but sell a similar hybrid tree called the London plane tree (Platanus x acerifolia). The London plane tree also has some problems, but cultivars such as ‘Bloodgood’ have some disease resistance.
Most of the shrubs I see listed on native plant lists are quite large. Are there any small native shrubs that will grow well in Baltimore?
Yes, there are several small native shrubs, but if you want a very compact shrub, you may need to select a cultivar of the native species.
Virginia sweetspire (Itea virginica) is native to the East Coast and parts of the Midwest and is generally found in wet areas. However, it is apparently quite adaptable and will grow in fairly dry conditions.
It typically grows up to 5 feet high, but can get much larger. If you want to be sure you are planting a compact plant, I would recommend the cultivar ‘Little Henry.’ It has attractive white flowers in spring, and excellent purple fall color. Another excellent native plant is summersweet clethra (Clethra alnifolia); however, the species plant will probably get larger than you wish. If you select this plant, you will have to purchase a compact cultivar such as ‘Hummingbird.’
‘Hummingbird’ grows to about 3 feet tall, has very dark green leaves, white summer flowers and yellow fall foliage.
1. Check all squash plants for evidence of squash vine borers. Damaged plant stems will appear wilted and have small piles of sawdust-like caterpillar excrement at their base. To control them, carefully slit the affected stems with a razor blade and remove the borers. Pile soil over the wounds.
2. Check all evergreen trees and shrubs for signs of bagworms. Bagworms can be controlled by hand picking, or by spraying with Bt (Bacillus thuringiensis), a microbial insecticide.
3. Remove spent blossoms on flowering annuals and perennials to promote vigorous plant growth and continuous flowering.
Dennis Bishop is an urban horticulture educator for the Baltimore office of the Maryland Cooperative Extension. If you have a gardening or pest problem, you can call the Home and Garden Information Center hot line (8 a.m. to 1 p.m. Monday through Friday) at 800-342-2507. You also can e-mail questions, order publications and diagnose plant problems by visiting the Web site, www.hgic.umd.edu.
- Sycamore Tree Problems – Treating Sycamore Tree Diseases And Pests
- Avoiding Problems with Sycamore Trees
- American Sycamore
- Sycamore anthracnose: Why your sycamore may be slow to leaf out this spring
- General Information on Sycamores
- London Planetree (Plantanus x acerifolia)
- Sycamore tree bark falling
- Weather-related disease problem on sycamore trees strikes this year
Sycamore Tree Problems – Treating Sycamore Tree Diseases And Pests
Tall, fast growing and durable, the sycamore tree—with its large, maple-like leaves—is an elegant addition to your backyard landscape. Its most recognizable feature is its bark that peels away as the trunk expands, revealing the white, tan and green inner bark. However, it is possible that you experience problems with sycamore trees. These can range from sycamore tree pests to sycamore tree diseases. Read on for information on sycamore tree problems.
Avoiding Problems with Sycamore Trees
Sycamore trees are vulnerable to diseases and insect pests, just like almost every variety of tree you can plant. Experts advise that you keep your tree healthy, with good cultural practices, as a first line of defense against problems with sycamore trees.
Generally, the healthier and more vital the tree, the less it will experience sycamore tree problems. However, even well placed, irrigated and fertilized sycamore trees can get some pests and diseases.
Sycamore Tree Pests
One of the most common sycamore tree pests is the sycamore lace bug that gets its name from the lacy pattern on the adult’s wings, head, and chest. The insects feed on the undersides of the sycamore’s leaves.
While the sycamore lace bug’s damage is rarely serious, a heavy infestation can slow the tree’s growth. Keep an eye on your tree leaves and wash off bugs with the hose. Insecticides are also available.
Diseases of Sycamore Trees
You’ll find that there are quite a few diseases of sycamore trees. The most dangerous of the diseases of sycamore trees is anthracnose, also called leaf and twig blight. It can kill American sycamore, although it does only minor damage to other varieties.
This disease can kill twig tips, expanding to buds, new shoots and leaves. The symptom you see most frequently is crinkling and browning of the leaves. This sycamore tree disease is most likely to strike when the weather is cool and wet. Spores from the fungus can be spread by rain and wind. If you give your trees sufficient water and fertilizer, you are unlikely to see this sycamore tree disease.
Another common disease of sycamore trees include powdery mildew fungus. It can be treated with fungicides.
Bacterial leaf scorch can also be a problem. It is caused by Xylella fastidiosa, a bacterial pathogen that kills off entire branches of the tree. Pruning infected branches can slow its spread.
Introduction: This massive tree has large attractive leaves and interesting fruit clusters that remain on the tree into winter. The long, stout trunk has beautiful exfoliating bark. The remarkable white, green and cream bark flakes off in patches and exposes the inner bark, making this a beautiful tree throughout the year. Culture: Although it prefers rich, moist soil, it idable to adapt to many soil or climatic conditions. Canker stain, verticillium wilt, powdery mildew, leaf scorch and sycamore lace bugs can be serious problems. This tree sheds tiny hairs, the cream-colored fuzz on its leaves and twigs, that may cause an allergic reaction, particularly during pruning. Leaf drop can be messy and chemicals released in leaves can prevent growth of the underlying turf. Shedding fruit clusters and bark can also be messy.
- Native habitat: Eastern U.S. in deciduous woods. Most abundant along streams and bottomlands.
- Growth habit: This large tree has a rounded, open, wide-spreading form and massive branches.
- Tree size: Known as a medium- to fast-growing tree, the London planetree can attain a height of 70 to 100 feet with a crown spreading to 65 to 80 feet.
- Flower and fruit: The small flowers are not showy but the bristly, rounded fruit are borne along a pendulous stalk. The 1-inch spiky brown balls persist into winter.
- Leaf: The planetree’s large leaves are maple-like although there is considerable variation in leaf shape and size. Fall color is not showy.
- Hardiness: Winter hardy to USDA Zone 5 (possibly 4).
The natural hybrid between American and Oriental sycamores (London planetree Platanus occidentalis x P. orientalis) has proven to be more disease resistant and commonly planted as a street, especially in Europe. It was first noted growing in London in the early 17th century. Because of its tolerance to soot and air pollution, it became the dominant ornamental tree in industrial London. Its tolerance of urban stresses quickly made it a popular.
- ‘Bloodgood’ – Considered a superior cultivar. Adapts well to difficult sites and is resistant to anthracnose blight.
- ‘Columbia’ – Pyramidal form, deeply lobed leaves; resistant to anthracnose and powdery mildew.
- ‘Liberty’ – Has a five-lobed leaf that resembles a large maple leaf. It is resistant to anthracnose and powdery mildew. Tree trunks exfoliate early in irregular sheets, exposing the light green under-bark.
- ‘Sutternii’ – An unusual cultivar with white exfoliating bark and variegated leaves.
The plane or sycamore family’s genus name, Platanus, is derived from the Greek name for the Oriental planetree (P. orientalis), platanos. The peeling bark is an outstanding winter characteristic. The bark of American sycamore is usually whiter than the greenish bark of the London planetree. A serious problem with all species of Platanus is anthracnose. Infection causes defoliation, then the shoot tips die, leaving many small twigs at the ends of the branches. It is best to select cultivars of London planetree that are resistant to anthracnose. The round fruit of London planetree is an aggregate of achenes (nut-like fruits). They tend to be borne singly on our native sycamore (P. occidentalis) and in multiples of two or three on the hybrid London planetree. Plants in this genus have some interesting anatomical features. A large leaf-like stipule can be seen along the petiole (leafstalk) under the leaf blade. The petiole is also interesting. It completely encloses the buds along the branch. You have to break away the leaf to see the buds.
Sycamore anthracnose: Why your sycamore may be slow to leaf out this spring
Michiganders in the lower part of the state have noticed their sycamores looking rather sickly this 2019 growing season. A cold, wet spring has caused many American sycamore trees (Platanus occidentalis) in the Michigan area to exhibit severe symptoms of a fungal disease called sycamore anthracnose. For example, a resident of Livingston County, Michigan, submitted a question to the Michigan State University Extension Ask an Expert group, noting that their 200-year-old sycamore tree looked sick and was “very light on leaf foliage.”
Sycamore anthracnose is caused by the fungal pathogen Apiognomonia veneta, which overwinters on dead Platanus spp. leaves, as well as in infected twigs and branch cankers. The pathogen starts reproducing from these sources to infect new leaves and shoots. Fungal spores are spread via rain splash as the new leaves and shoots emerge. Expanding sycamore shoots and leaves may quickly develop disease symptoms and die. Extended periods of cold spring weather slow growth of the sycamore tree. Meanwhile the fungal pathogen can grow further and kill dormant buds. All of this results in the very bare-looking sycamore trees that Michigan residents have noticed. Temperature and rainfall significantly impact the overall severity of this disease.
However, don’t panic, even in seasons with more severe infections, when the weather gets warmer and drier as the season progresses, anthracnose disease should abate, and the sycamores should put out a second flush of leaves by the end of the season. Mature leaves are naturally more resistant.
A London planetree in the foreground and poorly leafed out sycamore near the house. Photo by Rebecca Finneran, MSU Extension
One primary “management option” for sycamore anthracnose is to wait – the tree will likely recover with another flush of leaves. Other management options and Smart Gardening practices include collecting and disposing of diseased leaves at the end of the season; pruning out diseased and damaged branches, especially with smaller trees (remember to sanitize pruning tools between cuts); pruning for good air flow to reduce the leaf wetness period; watering your tree during droughty periods; and getting a soil test to determine whether the soil is lacking any nutrients needed for tree growth.
Fungicides are generally uncalled for to treat shade tree anthracnose on otherwise healthy trees, though fungicides are an option in certain cases. Examples of these cases would be if the trees are not well established or small, or unusually attractive trees that are very important to the aesthetics of the landscape.
If you are considering planting a new sycamore tree, you may want to opt instead for less susceptible London planetree (Platanus x acerifolia) cultivars, such as ‘Bloodgood,’ ‘Columbia,’ ‘Liberty,’ Exclamation! or Ovation. Oriental plane trees (P. orientalis) are also reported to be less susceptible to sycamore anthracnose, according to a Missouri Botanical Garden article, but would not be recommended for planting in Michigan since they are only hardy up to a United States Department of Agriculture (USDA) plant hardiness zone of 7, which is warmer overall temperatures than we experience here in Michigan.
- Sinclair and Lyon, Diseases of Trees and Shrubs, 2nd edition Cornell University Press, 2005.
- London planetree from The Morton Arboretum
- Platanus x acerifolia: London planetree from University of Connecticut
The sycamore (Platanus species) is a deciduous tree that is often grown for the shade it produces and the handsome bark on its massive trunk. There are 10 species, but this fact sheet will focus on one species and one hybrid that are common to South Carolina: American planetree (Platanus occidentalis) and London planetree (Platanus x acerifolia.) Both are adapted to all areas of South Carolina.
London planetree bark.
Karen Russ, ©2006 HGIC, Clemson Extension
General Information on Sycamores
Mature Height/Spread: Sycamore is a massive tree that grows 70 to 100 feet tall with a similar spread. It has a pyramidal form in youth but develops a spreading, rounded and irregular crown with age.
Growth Rate: This tree grows at a moderate to rapid rate, and has a moderate to long life span.
Ornamental Features: Sycamores are valued for their massive size and are often used as shade trees. The cream- to olive-colored exfoliating bark is handsome in all seasons, but it is exceptional in winter when contrasted with the dark bark of other trees in a woodland setting. The leaf size varies, even on the same tree, and the fall color is yellow-brown. The 1-inch fruit hang from the tree on long stalks through most of the winter.
Landscape Use: Sycamores are too big for most home properties. They are primarily used for parks, large-scale landscapes or naturalized plantings along streams. They have been used extensively as street trees, and although they withstand difficult city conditions, they can create problems that require high maintenance. Leaf and twig litter, disease and aggressive roots must be considered when choosing this tree for high-traffic (pedestrian and vehicular) areas.
American planetree leaves.
Paul Wray, Iowa State University, www.ipmimages.org
This tree prefers deep, moist, rich soils, but will grow in places undesirable to plant growth, such as areas with low soil oxygen and high pH. It prefers full sun or light shade.
Prune drooping branches on trees located near vehicular or pedestrian traffic. Eliminate the occasional double leader to promote a single trunk. Pruning healthy wood should be done in winter. Remove dead and broken wood when detected (any time of year) to reduce incidence of disease.
Problems: The most serious disease is anthracnose. Other diseases include canker, bacterial leaf scorch, powdery mildew and leaf spot. Insects that cause problems are aphids, sycamore lace bug, scales and borers. For more information on problems with sycamore, refer to the fact sheet HGIC 2011, Sycamore Diseases & Insect Pests.
Aggressive roots can raise sidewalks if planted too close. Plant at least 6 feet from the sidewalk or curb. Roots and dense shade created by the canopy of this tree prevent healthy growth of lawn grasses beneath it.
Keep this tree away from well-tended lawns, pavement and buildings. Sycamores create litter with their leaves, fruit and twigs. This is not such a problem when sited along streambanks or out-of-the-way places, but maintenance becomes an issue if located in turf areas or near pedestrian or vehicular traffic.
American Planetree (Platanus occidentalis)
The American planetree is also called sycamore, buttonwood and buttonball.
Mature Height/Spread: This tree can grow 75 to 100 feet with a similar or greater spread. Under ideal conditions it can attain heights of 175 feet and may have a trunk 10 to 14 feet in diameter.
Growth Rate: It grows at a moderate to rapid rate (2 feet per year) and is long-lived.
Ornamental Features: It is highly valued for its form and size, with its massive height and spread, huge trunk and large limbs. The growth rate rarely slows, and under ideal conditions this tree can become one of the most massive in Eastern North America. It usually develops one strong central trunk, but occasionally double leaders will develop.
The bark at the lower part of the trunk is red to gray-brown and scaly. The bark on the upper trunk peels in large flakes to expose smooth, lighter colored (white to creamy white) inner layers.
The leaves are cream-colored and wooly when they emerge in the spring. At maturity they are large, medium to dark green and are only wooly along the veins on the lower side. The fruit are seeds clustered into a round ball (1 inch) that hangs on a long, flexible stalk through most of the winter. They usually hang individually, but sometimes hang in pairs.
Landscape Use: The American planetree should be reserved for naturalized areas next to streams and rivers, or sites where litter and aggressive roots are not an issue. It needs ample space to develop.
This tree prefers deep, rich, moist, well-drained soils but will grow in almost anything. It grows in either high or low pH soils. Although it prefers moist soils, it tolerates moderate drought. It prefers sun or very light shade.
Problems: Anthracnose can be a serious problem in wet, cool springs. Bacterial leaf scorch, cankerstain, leafspot, canker and powdery mildew are other disease problems. Troublesome insects include aphids, sycamore plant bug, sycamore tussock moth, scales, borers and lacebugs.
Cultivars: There are no selections commercially available. When possible, select trees grown from parents native to your region.
London Planetree (Plantanus x acerifolia)
This hybrid is the result of a cross between P. occidentalis and P. orientalis. It is sometimes listed as P. x hybrida.
Mature Height/Spread: This tree grows 70 to 100 feet tall, 65 to 80 feet wide. It can reach 120 feet in height under ideal conditions.
Growth Rate: It grows at a moderate to rapid rate (2 feet per year) and has a moderate to long life span.
Ornamental Features: This tree is similar to American planetree with a few exceptions: The spread is not as great, bark is duller (but still showy) and fruit hang in pairs.
Landscape Use: London planetree should be reserved for naturalized areas next to streams and rivers, or sites where litter and aggressive roots are not an issue. It needs ample space to develop.
This tree prefers deep, rich, moist, well-drained soils but will grow in almost anything. It grows in either high or low pH soils. Although it prefers moist soils, it tolerates moderate drought. It prefers sun or very light shade.
Problems: London planetree suffers from most of the same disease and insect problems as American planetree. Cankerstain can be very serious on this tree. Some cultivars are somewhat resistant to powdery mildew and anthracnose. (Disease resistance means that infections are few, do not progress very far or do not occur.) Other problems with aggressive roots, litter and turf growth beneath the canopy are similar to American planetree.
- ‘Columbia’ and ‘Liberty’ are reportedly more resistant (not immune) to powdery mildew and eastern strains of anthracnose.
- ‘Bloodgood’ is somewhat resistant to anthracnose but susceptible to mildew.
Note: Chemical control of diseases and insects on large trees is usually not feasible since adequate coverage of the foliage with a pesticide cannot be achieved.
Now the Arboricultural Advisory and Information Service (AAIS) has sent out a warning that Britain’s sycamore trees are at risk of sooty bark disease (SBD).
Last year’s hot, dry and late summer has caused abnormal stress to many of the country’s oaks, leaving them more susceptible to pathogens which have a better chance of success on weakened trees.
If climate change warnings are borne out and the UK continues to experience the early arrival of spring followed by a prolonged hot summers and mild winters, the number of sycamore trees, a cousin of American maples, may be significantly reduced, according to the AAIS.
Dr Jean Webber, a tree pathologist with the Forestry Research, an agency of the Forestry Commission, said: “This fungus is what we call a latent pathogen – it can sit within the wood of a perfectly healthy tree for many years, still alive but not active. Then, when the tree is under a period of stress, particularly after we have a severe drought, it is able to gain the ascendency and bring the tree into a state of decline. When it manages to do that it is able to fruit, and we are able to see the nature of the disease on the bark, which it kills and causes large amounts to fall off.”
Experts say that the number of sycamore trees that will die from SBD will depend on this year’s weather. If this summer is hot and dry, the more advanced stages of the disease will become visible: as well as dead bark, the crowns of infected trees start wilting and the leaves will fall off before autumn.
SBD typically enters a tree through damaged bark or a break in a leaf stem. There is no treatment, making SBD impossible to prevent.
Dr Webber added: “The main recommendation is that if you are planting sycamore then you need to make sure it is mixed with other species so if you do lose them you don’t lose a whole tract of them in one area.
“It is really a case of accepting that this is something we will see with a hot summer, and, of course, if we are moving towards climate change with warmer summers, it may become more of an issue.
“People may then want to consider how much sycamore they want to plant in this country. It is about balancing the trees that we plant. Nowadays, no-one would think of planting a lot of elms.”
Wilt (fungus – Cephalosporium diospyri): This fungus has been found repeatedly in large sycamores. The fungus, when introduced into seedlings, produces symptoms including sudden wilting and browning of leaves, sudden blighting of twigs forming “shepherd’s crooks”, yellow discoloration, and defoliation. How widespread this fungus is in Texas sycamores is not known.
Botryodiplodia Canker (fungus – Botryodiplodia theobromae): This fungus is known generally as a weak or facultative parasite with a wide host range. However, in Texas it has caused a rapid death of sycamores. The fungus produces cankers on branches and the main stem. It is favored by high temperatures and drought stress conditions. Trees weakened by the Cephalosporium wilt fungus are more vulnerable to attack. Broken terminals in twigs are the best places for the fungus to enter. It has been a common problem in sycamores. Prune out dead and dying branches below the cankers. Sterilize pruning tools with 10 percent bleach solution between cuts. Spraying for anthracnose with benomyl will also help to control Botryodiplodia.
Sycamore Anthracnose (fungus – Gnomonia plantani): Sometimes called blight and scorch. A single attack seldom causes harm but if the tree is infected several years in succession it will weaken a tree, making it susceptible to borer attack and winter injury. The first symptoms, sudden browning of single leaves or clusters, may be confused with late frost injury. Later dead areas appear along or between the veins, usually starting at the leaf edge. Leaves fall prematurely when heavily infected and trees often remain bare until late summer, when new leaves form. Infection of small twigs causes sunken areas, called cankers, and slightly raised margins. When the canker completely girdles the twig, killing it, this is called the shoot blight stage. The fungus can overwinter in fallen infected leaves and in twig cankers. In southern Texas it can pass the winter in the spore stage on dormant buds. Severity of attack depends on weather conditions during the two week period following leaf emergence. Frequent rains and cool temperatures favor rapid spread. Below 55oF. injury will be severe and above 60oF, little or no injury. Control: Prune out dead twigs in fall. Burn all dead twigs and fallen leaves. Spray with recommended fungicide when leaves unfurl, when leaves are half-grown, and when leaves are fully grown. Trees repeatedly attacked should be well fertilized in spring to increase their vigor.
Leaf Spot (fungi – Mycosphaerella platanifolia, Phyllosticta plantani, and Septoria platanifolia): Several fungi cause disease of minor importance that can be controlled by the spray schedule suggested for control of anthracnose. Phloeospora multimaculans:known mainly in Texas. Irregular, dark brown to purple spots one-eighth to one-fourth inch in diameter on the upper leaf surface. Often with a brown center. Spots are brown with darker border on lower surface. Spots may coalesce to produce a dirty-brown colored leaf. Defoliation may occur.
Powdery Mildew (fungi – Microsphaera alni and Phyllactinia guttata): Makes appearance mainly in late summer. May be present on older growth but usually most severe on new growth, which may be distorted, stunted, and covered with a white growth and white spores.
Canker-Stain Disease (fungi – Ceratocystis fimbriata f. sp. plantani): It can be lethal to sycamore, but is much more important as a killing disease of London plane (Platanus acerifolia): Since it is spread almost entirely by man, through pruning, it is essentially a shade tree disease. Leaves are dwarfed and sparse in part or all of the tree top. The staining cankers occur on trunks or branches. The first symptom on the yellow or green bark is a brown to black lens-shaped discoloration. Cankers may become 20 to 40 inches long in one year, but usually only two inches wide. Cankers widen each year, and often coalesce, girdling the tree or branch. Older cankers shed their darkened, dead bark exposing the wood, which dries, cracks, and turns black. The reddish-brown or bluish-black discoloration of the wood, in cross section behind the cankers, is the most distinctive symptom. Stain patterns are radial, generally reaching the pith. The fungus sporulates abundantly on newly-killed wood in wet weather from May until October. It produces two kinds of asexual spores; one, long and clear; the other, short and brownish. It also produces a long-necked, pear-shaped, sexual fruiting structure. Avoid injuring the tree. Prune out dead limbs during winter. Be sure to dip the pruning tool in 10 percent bleach solution before each cut to avoid spreading the fungus. Treat cankers with protective paint.
Sooty Blotch (fungus – Gloeodes pomigena): Sometimes forms on shoots of sycamore. The dark surface mycelium can usually be rubbed off with the fingers.
Mistletoe (parasitic plant – Phoradendron serotinum): A seed-producing higher plant that parasitizes sycamore in the south.
Shoestring Root Rot (fungus – Armillaria mellea): Two forms of the fungus can usually be found under the bark at ground level. These are black “shoestring like” rhizomorphs and a white fan-shaped fungus growth. (See section on Mushroom Root Rot)
Cotton Root Rot (fungus – Phymatotrichum omnivorum): (See section on Cotton Root Rot)
Trunk Rots (fungi – Hydnum erinaceus, Fomes sp., Ganoderma sp.): Heart rot fungi can hollow out the entire central cylinder of a tree. The tree declines in general and the presence of the fungus is known when it fruits on the side of the tree. The annual fruiting structure is a white, rounded, spongy mass with long, slender white teeth on the bottom. There is no control – only prevention, by avoiding wounding the tree. (Fomes applanatus): This fungus enters wounds and causes a white, mottled trunk rot. The tree declines in general and the presence of the fungus is known when it produces a fruiting structure from a wound. This hard, woody, shelf-like perennial structure may attain a width of two or more feet. The upper surface is smooth, zoned, and grayish or grayish black, whereas the undersurface is white when fresh, but becomes yellowish with age. The undersurface turns brown when bruised and is a favorite medium for artists. There is no control – only prevention, by avoiding wounding of the tree.
Sycamore tree bark falling
Flaking bark is common for Sycamores, some years more than others. Sycamores grow quickly and can live for hundreds of years. With all the rain we have had this year; some trees have grown especially fast. As the girth of the sycamore tree expands, the brittle bark tends to crack and come loose. There is no cause for concern. If fact, the resulting green, white, and cream bark patches are quite beautiful
Basically, the bark of most young trees is smooth and thin. As the tree grows, the bark layer thickens with the outermost tissue eventually dying. Continued growth pushes the bark outward, sometimes causing the outer layers to crack. On some trees, the outer dead layers peel and drop off, revealing the inner layers of bark. Shedding or peeling bark is characteristic of trees such as the Sycamore. The grayish brown bark on a large sycamore tree, for example, flakes off in irregular blotches, revealing a cream or whitish gray inner bark. The loss of the outer layers of bark on sycamores is completely normal.
Additional information about Sycamore trees:
Bob Dluzen Special to The Detroit News Published 6:29 PM EDT Jun 6, 2019
The extra rain and cool weather we’ve been getting has been a mixed blessing. It’s June and a lot of gardens, farms and fields haven’t been planted yet because of saturated soil and cool temperatures.
On the other hand it has been great for established plants like trees and shrubs. In most cases they’ve made tremendous growth except for one notable exception — sycamore trees.
It’s quite startling to see how little progress the sycamore trees in our area have made. Most of them have very few leaves on them at all.
The maple tree on the left is flush with new leaves while the sycamore on the right is nearly bare. Bob Dluzen
This is due to a disease called anthracnose, a fungal malady of sycamores that is present in varying degrees from year to year. This year’s outbreak is particularly severe because of unusual weather.
A lot of it has to do with timing. Rainy and cool conditions that occur a couple of weeks after bud break allows the anthracnose fungus to thrive. The longer that type of weather stays around, the worse the infection gets. That’s why our sycamores are looking so bad for so long this year.
There’s really nothing practicable we can do to cure or even prevent this disease.
Witch’s broom caused by anthracnose Bob Dluzen
Fortunately, once it gets warmer and drier they’ll bounce right back. Most of the time, very little major damage is done to the trees. The most obvious permanent damage you’ll see is “witch’s broom,” a disfigurement of the branches that occurs in the spot the fungus killed twigs. At that point several small branches will grow from a single point giving it the typical witch’s broom appearance. Once the leaves fill out, however, the disfigurement is not so noticeable.
Witch’s broom caused by anthracnose. Bob Dzulen
Dead twigs eventually fall to the ground and can cause a mess in the lawn. This is probably why some people think of sycamores as messy tree, but it’s not the poor tree’s fault.
Trees can be sprayed or treated but it really doesn’t do much good since the infected parts can’t be healed anyway. Waiting for the weather is the best course of action in most cases. It extremely rare for a tree to die from anthracnose unless it is under stress from something else, such as being planted in the wrong area, or it has a lot of bark damage from lawn mowers.
A little bit of fertilizer may help your tree to grow back its leaves faster. Generally, trees growing in lawns will get the nitrogen they need from the fertilizer used to fertilize the grass.
Anthracnose will always be with us, so it’s just something we’ll have to live with.
Published 6:29 PM EDT Jun 6, 2019