Tree Diseases Archives - Barts Tree Service

DISEASE ALERT – Beech Leaf Disease in Fairfield & Litchfield Counties, CT

Dark stripes on BLD-infected beech leaves viewed from below.

If your beech tree has dark lines on its leaves, it’s probably suffering from Beech Leaf Disease (BLD).

Since it was first discovered in Ohio in 2012, BLD has quickly spread to other states. Scientists from Connecticut’s Agricultural Experiment Station first verified Beech Leaf Disease near Stamford, Connecticut in 2019.

Beech Leaf Disease is now found on American beech (Fagus grandifolia) throughout Connecticut. Symptoms are most severe in Fairfield, New Haven, Middlesex, and New London Counties.

Learn the most up-to-date news about beech leaf disease in Connecticut, including:

How to recognize beech leaf disease,
Which types of beech tree this disease affects,
What causes BLD,
Treatment options (hint: there currently aren’t any),
Preventing beech leaf disease, and
What to do if you spot signs of beech leaf disease on your trees.

Not sure if you have beech trees on your property? Check this beech tree identification guide.

Dark, curling leaves are a symptom of beech leaf disease.

Dark, curling, and deformed leaves are a symptom of Beech Leaf Disease.

Symptoms of Beech Leaf Disease

While some aspects of Beech Leaf Disease may look similar to other tree problems, there are distinct symptoms that clearly identify the issue as BLD. If you notice any of the following symptoms, call a Certified Arborist for a tree inspection and diagnosis.

Dark stripes on leaves – Beech leaf disease is best identified by bands of dark green tissue between the leaf veins. Stand under your tree and look up at the tree canopy; if any bands are present on the leaves, they’ll be more easily seen that way.
Thicker leaves – Infected leaves (those with dark stripes) tend to become thicker and have a leather-like consistency.
Curling leaves – Beech tree leaves may also begin to curl as the disease progresses.
Stunted leaf buds – As new growth emerges in spring, the buds will be smaller and have a yellowish tinge.
Smaller leaves – New leaves on affected trees tend to be significantly smaller than the previous leaves.
Branch and tip dieback – Smaller branches start to die from the tip.
Canopy thinning – The striped, curling leaves will eventually drop, and fewer new leaves will grow. All of these things lead to the entire tree canopy appearing thinner and less dense.
Dying trees – Young trees typically die from beech leaf disease within two to five years of becoming infected. Larger trees may survive up to six years.

Beech Leaf Disease often spreads from the base of a tree’s crown to its top, but there is no consistent pattern.

You may see healthy leaves interspersed with mildly or severely diseased leaves on the same twig or branch anywhere on a beech tree. It can be hard to spot Beech Leaf Disease in a large tree’s crown if there are only a few scattered areas of leaf damage showing.

Symptoms observed in foliage this year are the result of an infection that started last year. In autumn, nematodes migrate from infected foliage into nearby buds, where they overwinter and reproduce. When buds start to grow in spring, they’re already damaged, leading to stunted growth and smaller leaves.

BLD Has Worsened in CT in 2022

Symptoms of BLD have been particularly severe this year. Many leaves didn’t sprout at all, and the leaves that did grow were so damaged that they almost look waterlogged. We’ve seen leaves starting to fall as early as June. What’s been especially shocking is the impact on large trees – some have just a quarter of the canopy they usually have.

Beech Bark Disease Makes Trees More Susceptible to BLD

Many older beech trees are already impacted by another serious disease, called beech bark disease.

This unusual disease is caused by a combination of a scale insect that feeds on beech trees and a native fungus that ultimately kills the tree. The insect wounds the bark while feeding, leaving an entry point for the fungus. Over time, the combination results in extensive areas of dead bark and eventually kills the tree.
Researchers believe that bark disease weakens beech trees and makes them more susceptible to severe effects caused by beech leaf disease.

Types of Beech Trees Affected by BLD

Beech leaf disease currently only affects beech trees, but it impacts all varieties, including:

American beech (Fagus grandifolia),
European beech (Fagus sylvatica), including the ornamental copper or purple beech, and
Oriental beech (Fagus orientalis).

According to the U.S. Forest Service’s inventory data (from January 2021), the American beech is the third most abundant tree species in Connecticut, after red maple and black birch. Beech trees are found in just over 40 percent of the state’s forested lands and researchers estimate that Connecticut has about 57 million beech trees in total. Given the high mortality rate of BLD-infected trees, we could be facing a huge die-off that will completely change the makeup of our native forests.

Dark stripes on beech leaves are signs of beech leaf disease.

Dark stripes on beech leaves are a sign of beech leaf disease. Image courtesy of Dr. Robert E. Marra, Connecticut Agricultural Experiment Station.

Causes of Beech Leaf Disease

Beech leaf disease is caused by a foliar nematode (microscopic worm) called Litylenchus crenatae subsp. mccannii.

Researchers aren’t entirely certain how the nematode spreads, but it does travel on water. It’s possible that frequent or heavy rains allow the nematodes to spread more easily, leading to more widespread and severe effects the following year.

Beech Leaf Disease has been found on isolated islands, such as Fishers Island 2 miles off the Connecticut coast. As a result, scientists speculate that the nematodes may also be carried by birds.

Beech Leaf Disease Treatment Options

As of the writing of this article, there is no treatment for beech leaf disease. Different treatment methods are being tested but nothing has yet been proven effective.

The one option that shows some promise involves treatments with a phosphonate-based product. However, it’s not a matter of treating your beech tree once and thinking it’ll be protected. Because BLD is widespread in forests, the nematode that causes the disease will continuously affect landscape trees – even those that have received treatment. This means that controlling the disease on your property will require ongoing, long-term treatment.

The tree care professionals at Barts Tree Service are monitoring the news about this and other tree issues. We’ll keep you posted about any new BLD treatments and will offer treatments that have been proven effective as soon as they become available.

Call us to schedule an inspection and to learn the latest updates on beech leaf disease in the Fairfield County and Litchfield County areas.

Preventing Beech Leaf Disease

Until there is a proven treatment for beech leaf disease, your best bet is to focus on prevention.

Keep Your Trees Healthy

Pests and diseases are more likely to attack trees that are already stressed. Proper maintenance, watering, and pruning can all help to keep your beech trees healthy.

Adding organic mulch around your trees can also protect them. Plus, it will add nutrients to the soil, as long as the mulch is applied correctly.

Fertilization may also benefit any trees that need a little extra TLC.

Check Your Beech Trees Regularly

Periodically check your beech trees for any symptoms of beech leaf disease.

Beech trees can suffer from other issues, such as beech bark disease, so it’s important to promptly treat any destructive pests or diseases on your trees.

Contact Barts Tree Service

With the many tree pests and diseases prevalent in our area, it can be difficult to tell what’s affecting your trees.

That’s why we offer professional pest and disease diagnosis through our consultations and tree health management services.

Trees are a valuable resource and we want to help you keep yours healthy and strong!

Contact us today to request your professional tree evaluation.

White Pine Needles Turning Yellow: White Pine Decline in CT

We’ve had a lot of reports recently about problems with white pines in southern New England, including here in Connecticut. The pine needles, especially the older inner needles, are turning tan or yellow and then falling off, and the trees are looking generally unhealthy, thin or even dying.

Why Are White Pines Shedding Needles?

The pine in the middle of the photo is showing signs of decline, with many yellowed and missing needles.

Unfortunately, it’s not entirely clear what’s causing the problem.

We have had a fungal condition called needlecast in the area for some time which has had minor effects on conifers but now it appears that there is a new combined force which includes four fungi associated with this new condition, including one that was only discovered in CT last year. Each one of those can cause pine needles to turn yellow and eventually fall off, but not all are always found on declining pines.

Another factor is the weather conditions over the past few years, especially the very dry conditions of 2015. However, we’re seeing signs of needlecast on this year’s needles, which suggests that there are things beyond last year’s weather that are affecting our white pines.

The CT Agricultural Experiment Station has a brief update on white pine decline released through the Plant Disease Information Office.

There’s also a helpful document from the UMass Extension office that includes photos of affected trees.

What Can You Do About It?

That’s not an easy question to answer.

Because the fungi associated with white pine decline may not always be present and a true understanding of the root cause is still developing, a fungicide treatment may not always be effective but can be helpful in protecting new needles.

It’s a good idea to have a professional examination of your pine tree(s) before deciding on treatment.

And because affected trees are more susceptible to stressors, such as dry conditions, be sure to keep your pines adequately watered to ensure vigor (but do not water the branches or needles! its best to utilize a soaker hose).

For more information on pine needlecast problems, see our related article on Evergreen Needlecast: What You Need to Know.

Evergreen Needlecast: What You Need to Know

Tree showing dying patches due to needlecast.

This last year was brutal on evergreens with a very wet spring that launched a fungal attack that took a great toll on our spruce trees. We saw very high levels of needlecast disease spreading all over the county.

What is Evergreen Needlecast?

As the name implies, affected evergreens cast or lose their needles and look sickly, very thin and browned out.

If you take a closer look, the individual needles will have brown bands or blotches up and down the needle that can be black, red or brown. This is caused by several different fungi bodies attacking the needle and then killing it so it falls off.

We typically see the emergence of needlecast and visible signs of the fungal fruiting bodies in spring to early summer.

Now with spring finally here, we will start the wet season where needlecast will bloom again. We usually see it in evergreens that are planted in rows and rather close together or in shaded areas. When there is rain it takes a long time for the needles to dry from sun and wind – and we all know that fungi love dark, moist areas!

Treatment for Needlecast

Striped needles due to needlecast

If we spray a fungicide on the trees we can prevent any new growth from getting needlecast fungi and restore a green healthy looking tree.

When to Treat

These treatments usually start in the beginning of May and continue every two weeks until we start to dry out going into summer.

Length of Treatment

Because of the needlecast life cycle, it is usually most effective to continue treatments for two years.

Tips to Prevent Needlecast

Do not prune evergreens during the wet spring timeframe since you will spread the fungal spores between cuts.

If it is necessary to prune, be sure to prune in the afternoon during sunny days. Start with healthy trees then move on to the diseased trees.

Also be sure to sterilize cutting tools with denatured alcohol or a 10% bleach mixture between cuts – and sterilize them carefully after you’ve finished pruning.

If you have an irrigation system, make sure it is adjusted so it does not spray on the foliage of your evergreens since this will create the perfect environment for fungal out break.

Protect Your Ash and Elm Trees

Our area here in southern Connecticut is being attacked on several fronts by invasive pests as seen by DEEP quarantines in recent news articles. Most notably, Emerald Ash Borer (EAB) and Dutch Elm Disease (DED) have become widespread, potentially eliminating these trees from our forests and landscapes forever.

Don’t let your trees die from something that can be prevented! The arborists at Barts Tree Service have a solution to help fend off these attacks for municipalities, homeowners, and golf courses.

We are currently treating trees with a systemic trunk injection that can word off these attacks before the pests arrive. We also work with you to remove some already infested trees so as to maintain healthy trees going forward.

What’s So Special About Trunk Injections?

Arborjet trunk injections seal formulations directly inside a tree’s vascular system, assuring an accurate dose that moves quickly to the target. Trunk injections limit the need to make foliar or soil applications (no spraying of toxic chemicals!), and research shows greater efficacy with trunk injection versus spraying.

Here are some of the benefits of the Arborject trunk injection treatment for Dutch Elm Disease and Emerald Ash Borer:

Fast acting – because it’s injected directly into the vascular system of the tree
Highest effectiveness – as proven by several university research programs
Environmentally responsible – no spraying so with no residual chemicals outside the tree
Long lasting – up to 2 years per treatment

To see if your tress can be saved, or to prevent them from becoming infected, contact the arborists at Barts Tree Service for a free consultation. You can always reach us at 203-240-1302.

For More Information

To learn more about EAB and Dutch Elm Disease, including identification, prevention, and treatment, please click on the links below.

The video below will show you more about our trunk injection system.

Dutch Elm Disease

The rise of Dutch Elm Disease (DED) has been a devastating event in the history of tree diseases. It is caused by the fungi Ophiostoma novo-ulmi and O. ulmi and is carried by bark beetles. The disease affects American elms (and other elm species, to a varying extent), killing individual branches and eventually the entire tree within one to several years. The disease is referred to as “Dutch” Elm Disease because it was first described in Holland in 1921, although the pathogen originated in the Orient. The disease began its destructive reign in the United States in 1930.

Prior to the arrival of this pathogen, many streets and parks were graced by the upright and spreading branch structure of American Elms. The appearance of a mature American Elm can make nature lovers stop and stare in awe. Due to the incredible interest in these trees, plant breeders have been trying to develop resistant American Elms for years. Unfortunately, many of those trees proved to be susceptible to other diseases, such as Elm Yellows.

Symptoms of Dutch Elm Disease

Flagging elm branch – a symptom of Dutch Elm Disease

Symptoms develop quickly within a 4-5 week period and usually when the leaves have reached full size. The first visual symptom usually observed within the crown of the tree is referred to as “flagging”. This occurs when one or more branches develop symptoms of wilting and/or yellowing of the leaves on a otherwise apparently healthy tree.

Prior to these visible external symptoms, symptoms have developed internally and include the death of xylem cells, the loss of water conducting ability within the tree, and the browning of the infected sapwood in narrow streaks that follow the wood grain. The fungus is present in the streaked wood, and samples taken from this symptomatic tissue are needed to confirm infection by this pathogen. Blockage of xylem vessels is due to the production of gums and tyloses. In the Western U.S. where summers are dry, water shortage and heat stress often mask symptoms.

Lifecycle of Dutch Elm Disease

Left trunk: Native elm bark beetle galleries;
Right trunk: Smaller European elm bark beetle galleries.

Spores of O. novo-ulmi are stored in xylem vessels and reproduce through budding. Dispersal of spores is via bark beetles that burrow under the bark and lay their eggs in wood galleries. Elm bark beetles distribute O. novo-ulmi locally and over distances of several miles while the fungus may be distributed over longer distances in elm logs and in firewood. There are two species of beetle vectors known in North America, Hylurgopinus rufipes and Scolytus multistratus. Insects are attracted to healthy elms by volatile chemicals produced by the trees. Beetles bore into the inner bark and while feeding deposit spores of O. novo-ulmi. Scotylus multistratus feeds in the crotches of twigs, therefore, most infections occur in twigs. Hylurgopinus rufipes bores in the bark of branches and small trunks causing infections in major branches.

From the point of inoculation, the fungus moves upward and downward by two modes: in the liquid within xylem vessels and by the growth of fungal hyphae between xylem vessels after germination. Ophiostoma novo-ulmi reaches the roots within one season of infection where it continues to grow. The fungus grows in the roots and ascends the trunk in a wave of infection that kills the entire tree or a major part of it. Where elms are planted close together and there is a possibility of root grafting, O. novo-ulmi may move from one tree into the next through the roots. The fungus can also survive as a saprophyte in dead plant tissue.

Preventing Dutch Elm Disease

Smaller European Elm Bark Beetle

Never transport elm wood or wood products with bark to new locations. Many landscape and forest pests can be spread in firewood. Leave your fire wood at home and pick up local wood when camping or traveling. Don’t take extra fire wood home with you.

There are systemic fungicides and injections that can be made by arborists that sometimes (depending on stage of disease) can help prolong the tree’s life. However, once a tree is infected, there’s no known cure for Dutch Elm Disease.

Black Knot Disease in Cherry Trees

Black knot of plum and cherry trees is a widespread and serious disease throughout North America. The black knot fungus mainly affects twigs, branches, and fruit spurs, although sometimes trunks may also become diseased. Usually, infections begin on the youngest growth.

Black knot disease in cherry trees is easy to recognize

What Black Knot Looks Like

Black knot is visible as knots or elongated swellings which form on the twigs and branches. The knots develop into black, corky, cylindrical galls that range from about 1/2 to 1 1/2 inches in diameter and may be more than 12 inches long. Branches beyond the galls are often stunted or dead. Smaller twigs usually die within a year after being infected. Larger branches may live for several years before being girdled and killed by the fungus. The entire tree may gradually weaken and die if the severity of the disease increases and no effective control measures are taken.

Black knot is caused by a fungus that multiplies during wet spring weather. The visual symptoms are often seen 6 to 12 months after initial infection.

How to Control Black Knot

To control black knot, prune out and destroy infected twigs and branches in the fall and winter by burning or burying the pruned knots. Be sure to cut at least 4 inches below the visible signs of the knot. Large knots or cankers on main branches or the trunk should be cut out to a depth of at least 1/2 inch beyond the infection.

After each twig branch cut, be sure to sanitize your pruning tool in a mixture of 1 part bleach and 6 parts water as this helps to reduce the spread of the fungus.

In the spring spray the tree with fungicide for fruit and ornamental trees. Two or three more sprays at intervals of 7 to 10 days are required during the spring season.

What’s Killing Our Ash Trees in Connecticut?

The suspected killer is called ”ash yellows,” and is increasingly thought to be at work in the majority of cases of decline that have struck white ash trees.

Once an ash has ash yellows, there’s no way to cure it. Instead of living to 100 years or more, white ashes – valued for their fast growth and used to produce baseball bats and hardwood floors and furniture – seem to die within 10 years.

Decline among ash trees, which along with oaks, maples, beeches and birches are commonly found in Connecticut and throughout the Northeast, is not a new phenomenon. Scientists first noticed it in the 1930’s and believe that ”ash dieback” has progressively spread throughout the northeastern states and parts of eastern Canada. It’s progressively getting worse and unlike cases where trees can be sprayed to ward off more common fungus-related diseases, spraying an ash tree to prevent ash yellows is futile.

For decades drought conditions and various viral conditions were thought to be at work in ash decline, but research has settled on another culprit with the ungainly name of mycoplasmalike organism, or MLO. Simply put, MLOs are single-celled bodies that resemble amoebas and invade the food-conducting tubes of trees. With ash yellows, they eventually produce a variety of nasty symptoms: clumps of twigs known as witches’-brooms, stunted branches with leaf bunches at the ends, sprouts on trunks and the discoloration of the green leaves that gives the disease its name. The organisms are believed to be passed from tree to tree by leafhoppers – insects that suck material from one plant and then pass it to another.

One clue to the origins of ash yellows may come from studying peach trees in our area, which have been dying for years from something called x-disease, also thought to be caused by an MLO. Nobody knows whether it’s all the same or each one is genetically different at this time.

Although injecting antibiotics into other trees suffering from MLO-related diseases has temporarily halted decline, even if the right substance could be found it would be impractical since it would have to administered year after year. Because there is little chance of prevention, it is thought that the best hope for halting the spread of ash yellows is identifying genetically resistant trees and then propagating them.

Between Ash Yellows (MLO) and the Emerald Ash Borer (EAB) the ash tree has a very bleak future ahead.

If you notice your ash tree suffering from “ash yellows” and you are seeing a steady decline in foliage you only have a 1-3 year window generally for when the tree will die. I would recommend removing the tree prior to it dying since it is structurally safer to work with and will save money versus taking down a completely dead tree.