Bacterial Leaf Scorch
Singed brown edges on leaves of trees is called scorch and is caused by various stresses including drought, root growth restriction, compacted soil or even salt damage. This can also be caused by a disease known as Bacterial Leaf Scorch (BLS) which infects Oak trees as well as Maples, Lindens, Elms and others, although it is more commonly found in Oaks, especially Red Oaks. Leafhoppers, spittle bugs and other xylem feeding insects carry the bacteria from tree to tree.
This pathogen restricts the flow of water and nutrients to the leaves which causes the scorched leaf effect. Leaves of trees infected with BLS develop normally in the spring but start to show signs of scorching by August or September. This disease causes the margins (outside edges) of the leaves to turn brown. Unlike with Oak Wilt, when trees are infected with Bacterial Leaf Scorch there is often a yellow, or reddish band between the green leaf center and it's brown margin. Quite often the effected leaves will drop prematurely in the early fall. These symptoms worsen during drought conditions. When a tree first becomes infected with BLS, only a few branches of scorched leaves may be seen. As this disease progresses, it gradually spreads throughout the tree. Smaller branches will die first, and within a few years, larger and larger limbs will die. Bacterial Leaf Scorch, if left untreated, will slowly kill the tree.
Oak or other trees showing signs of BLS should be protected from stress whenever possible, such as watering in times of drought. For positive identification, Plant Health Solutions can send leaf and twig samples to the lab to be tested for this pathogen. To save trees infected with Bacterial Leaf Scorch it is important to start treating before the disease has progressed to an advanced stage. This pathogen can never be cured, but if caught in time, and treated annually with systemic antibiotic treatment by a certified applicator, it can be effectively suppressed. Growth regulator injections have also been shown to help reduce Bacterial Leaf Scorch by inhibiting synthesis of the plant hormone gibberellin. This chemical suppresses shoot growth and stimulates root development which helps to increase the uptake of water and nutrients to the canopy.
My husband and I are delighted with Plant Health Solutions! We have three huge oak trees surrounding our house; they are beautiful to look at, animals love them, and their shade keeps our utility bills really low in the summer. When Peter Benz was at our home to check on a different tree, he pointed out to us that those oaks had bacterial leaf scorch, even though neither my husband nor I could tell they were even sick. Peter told us that he could save these trees for us if we let him start treating them right away. We agreed, and are we ever glad! Neighbors all around us -- behind us, on either side of us, across the street, down the block -- have all lost their big oak trees. Ours are still going strong because Plant Health Solutions started treating them before they looked sick. I would recommend Plant Health Solutions and Peter Benz to anyone who loves their trees.
-Mandy G. (Hatboro, Montgomery County)