Signs of Tree Disease and Pests

Signs of Tree Disease and Pests

Summer is the season for your trees. You can tell they’re enjoying the rain and sunshine by their bounty of leaves and rich coloring. But what if your trees are trying to tell you something else? Let’s take a look at a handful of tree disease and pests indicated by falling needles, brown leaves and rotting fruit.

Falling Needles

Have you noticed yellow spots on your Scotch or red pine needles? Perhaps these needles also completely yellow before darkening and then falling off. It could be brown-spot needle blight. If left untreated, growth will slow or stop completely and the tree could die. Symptoms appear anytime between May and October.

Have you noticed yellow or reddish-brown spots on your tree needles, particularly if your lawn has Scotch, Austrian and red pines? It could be Lophodermium needle cast. This is a fungal disease that brings about fruiting bodies on the needles that often split and release spores. Symptoms typically appear in early spring but are more prevalent by late summer or fall.

Brown leaves

Have you noticed leaves on your elm tree starting to turn yellow and wilt? Perhaps they’ve turned brown completely. It could be Dutch Elm Disease (DED), which is a fungus that is carried by the elm bark beetle. An infected tree could die within a year if it is particularly susceptible to DED. Learn more about DED here.

Have you noticed large, brown blemishes on your oak tree leaves? This may also be accompanied by brown veins. It could be Bur Oak Blight (BOB), a fungus caused by an unnamed species of Tubakia. Symptoms typically appear in late July or August and, if left untreated, worsen until the tree dies. Read about BOB here.

Rotting fruit

Have you noticed brown rotted spots slowly consuming the fruit on your trees, particularly those growing stone fruits (peaches, cherries, etc.)? It could be brown rot. If properly treated, this fungus will be less devastating but prevention is key with brown rot. Removal of fruit at the end of the season, regular fungicide treatments and pruning are all important steps in the prevention process.

Have you noticed round fuzzy spots that are yellow green on the leaves and fruit of your tree? These spots may also darken and turn completely yellow before the leaves and fruit drop from the tree by mid-summer. It could be apple scab, which hosts include crab apple and mountain ash trees. While apple scab is not always deadly, it can lower the amount and quality of the fruit produced by the tree.

If you suspect any of these signs of disease or pests, contact us right away. We’d be happy to provide a free consultation and our certified arborists have the knowledge and experience needed to help your trees thrive.

Rotten fruit on a diseased tree

Leave a Reply