Bacterial leaf scorch (BLS) is a systemic, chronic disease that can be fatal for the affected tree. So, you should look for the signs and consider management. Plus, you may need to decide whether to have it removed by hiring tree removal services. Below is a guide to BLS.

What Is Bacterial Leaf Scorch?

BLS is a chronic condition that can mainly affect various types of oak and maple trees. It can infect red, shingle, pin, bur, and white oak trees, while red and sugar maples are also common targets. Other affected trees can be: elm, sycamore, sweetgum, and mulberry trees. Moreover, certain food and crop plants can be the hosts of BLS as well, such as pecan, peach, blueberry, and plum.

Bacterial leaf scorch is caused by the bacterium Xylella fastidiosa. When it gets into a tree, it affects the xylem tissues that are responsible for water and nutrient transport to all the parts of the tree. This restricts the water and nutrient supply of the tree, and it may look like the tree is dealing with drought stress.

BLS can slowly decline a tree’s health and cause its death within 3 to 10 years. So, a BLS-affected tree can become a hazard and you should take care of it by first spotting it and then managing it.

Signs Of Bacterial Leaf Scorch In Oak, Maple, And Other Trees

Scorched Leaves With Yellow Area

Scorched tips of the leaves are a common sign of bacterial leaf scorch, even though the sign itself is not specific to BLS. Any tree problem that involves the disruption of the water supply system of the tree can create similar signs. However, in BLS-affected trees, the scorched part of the leaf will have a yellow area between the scorched area and the green area (if any).

Moreover, there won’t be any spots on the scorched part of the leaves. You won’t see any black dots, powdering layers, or anything else on it. Also, the scorching of each leaf will be uneven. You may even see one side of the same leaf to be scorched and the other side to be green.

The Symptoms Appear On A Single Branch First

In early stages, the scorched leaf symptoms are on a single branch only. This slowly spreads and affects other branches and their leaves.

Older Leaves inside The Canopy Are Affected First

You will also notice that leaf browning and scorching start from the leaves inside the canopy. Outer leaves show the effects much later in most trees. Sometimes, a year or two after the infection.

Note that the entire or most parts of the tree canopy turning brown or scorched suddenly is not BLS. It can be drought or oak wilt. However, if it happens over a few years, it can be BLS.

Leaf Scorching And Premature Leaf Drops Returns Every Year

As this condition affects trees over a few years (3-10 years), the signs will return each year with more intensity than the last time. This can also help you differentiate between drought and BLS, because in drought-stressed trees, watering, rain, and other factors can fix the problem. However, in BLS, the condition will keep returning every year, affecting more branches than before.

Branch Dieback

As the branches and leaves are affected because they can’t get the water supply from the trunk or roots, branch dieback may occur from the second or third year. It’s more visible and severe from the third year and keeps becoming worse every year.

You can perform a snap test to detect branch dieback and dead branches. Try to bend a twig that doesn’t have leaves anymore. If it snaps without any effort, it’s dead. On the trunk, you can test it by slightly peeling a small section of the outer layer. A green and moist internal layer shows that the area is fine, but a dry and brown internals mean that part of the trunk is dead. The tree may be hazardous at this point. So, consider hiring emergency tree services Chevy Chase.

Worse Symptoms During Summer And Early Fall

The scorched leaves, leaf browning, and leaf drops will become worse from mid-summer to the early fall season. This is due to the increased water demand in the summer. As the water transport system is clogged by the bacteria, the tree can’t supply water and nutrients to all of its parts, which worsens the symptoms.

Another reason is that the bacteria growth maximizes during the spring to summer season. So, the effects appear more acutely in the summer and early fall.

Diagnosis

The above-mentioned signs may help in spotting a problem, but as the symptoms of BLS are similar to some other tree issues, like drought stress, heat stress, oak wilt, and Dutch elm disease, you should confirm the problem by sending the samples to a laboratory or hiring a tree expert.

The best time to look for symptoms or to send samples is during the summer and early fall. This is the time when the signs are severe.

Should You Remove A Tree Infected By Bacterial Leaf Scorch?

The removal of the tree should not be decided solely on the single reason that it has BLS. As BLS is carried by insects, like leafhoppers and spittlebugs, even if you remove an infected tree, it may not affect the risk of BLS spreading to other trees.

Therefore, you should take into account the health of the tree and whether it’s structurally sound or not. This is because bacterial leaf scorch spreads inside a tree over 3-10 years. So, removing a tree when it’s only developing the symptoms isn’t usually recommended because with proper tree care, you can still have the tree in your yard for years before needing to cut it down.

You should only remove a BLS-infected tree if:

The tree has a confirmed BLS infection.
It’s been at least more than 4 years that you’re seeing the symptoms of BLS.
When you scratch the trunk, it’s dry and brown.
There’s extensive dieback.
Most or the entire canopy of the tree is severely affected.
The tree is showing signs of structural problems and poses a safety risk to the surroundings and people.
The tree’s health is declining and other pests are infesting the tree.
The tree is leaning.

How To Treat Bacterial Leaf Scorch?

BLS is incurable. But as it progresses slowly, you can manage the symptoms to extend the life of the affected tree by:

Watering the tree extensively during the summer and autumn seasons.
Creating a 2-3-inch layer of mulch around the tree.
Pruning deadwood regularly and sanitizing the tools with bleach or rubbing alcohol between each cut.
Administering antibiotic injections. A tree expert can inject antibiotics into the tree to minimize the symptoms. These injections are administered yearly during late spring or early summer.

Conclusion

Bacterial leaf scorch is a chronic and fatal tree disease. So, you should look for the above-mentioned signs to spot and manage it. You can keep the tree for a few years as the disease progresses over 3-10 years. But if the tree is showing signs of decline, hire tree cutting services Kensington for removal.