Resources for managing and stopping spotted lanternfly are growing almost as quickly as this pest is spreading. We report on new resources for protecting your plants!
Oak wilt has been found in most counties in Indiana and is one of the most serious threats to the health of oak trees in the Midwest, especially those in the red oak / black oak group. The disease is caused by the fungus Ceratocystis fagacearum and is spread from tree to tree by sap feeding beetles and by natural root grafts between trees. Beetles carry spores of the fungus from infected trees to fresh wounds leading to infections in the canopy. Root of oaks of the same species nearby normally join as grafts when they grow together, providing the other means of spread from one infected tree to other nearby oaks. Trees in the red oak and black oak group are highly susceptible. When infected early in the summer red oaks usually wilt rapidly, show extensive summer leaf drop and may die by fall, or spring of the year[Read More…]
Boxwoods losing leaves should not be ignored!! Check them carefully for tell-tale symptoms of boxwood blight, a serious fungal disease that causes rapid defoliation and dieback (Fig. 1). The fungus that causes boxwood blight can infect all above ground portions of the shrub. The first symptoms of the disease are dark leaf spots (Fig. 2 ) that progress to twig blight and rapid defoliation (Fig. 3) and eventual death of the plant if it goes undetected (Fig 4). The narrow black streaks (cankers) that develop on green stems (Fig. 5), are a unique symptom that differentiates boxwood blight from other boxwood diseases. During periods of high humidity, white, fuzzy masses that consist of numerous clumps of spores will emerge from these black stem cankers (Fig. 6) as well as on the underside of leaf spots. The spores can be observed on infected stems and leaves with a hand lens. These[Read More…]
Tree inspections are important for every tree owner to protect people and property and reduce liability.
An abiotic stress in plants is a stress due to a non-living factor, such as temperature, moisture, herbicides, etc. Biotic stress includes a living organism, such as a fungi, insect, etc. This series will explore some of the most common types of abiotic stress you may find in landscapes and nurseries. What is wrong with this maple? How would you correct the problem? If you guessed manganese deficiency, you would be correct. In areas with high pH, such as many locations in the Midwest, manganese (Mn) deficiency in maple is very common. When the pH of the soil is above 7, manganese is not readily available to the plant, even if there are sufficient amounts of manganese in the soil. As the pH of the soil increases, manganese is less and less available. We tend to begin seeing manganese deficiency when the pH is above 6.3 (Fig. 1). [Read More…]
Q. We have a large sycamore tree in our yard. Every summer it sheds its bark over a few weeks’ time. I think as it grows it is growing new bark and losing the old bark. Am I correct? – J.C., Walton, Ind. A. You’re on the right track. Peeling bark is normal, and is a key ornamental characteristic for a sycamore, also known as American planetree. The bark starts out a bit gray-brown and as the bark matures, the outer layer peels off in large sheets to reveal a lighter-colored, creamy, off-white inner layer. The result appears a bit like a camouflage pattern. No need to worry – the tree is not harmed by the peeling bark.
Getting calls from panicked customers about black spots on maple leaves? You’re probably not alone, because now is the time when people start to notice maple tar spot. Every summer we get questions about black spots on maple leaves that look like tar. These spots are not actually “tar” on maple, but are rather a fungal disease known as tar spot. These photos show a range of symptoms presented by this disease. Tar spots on maples are caused by fungi in the genus Rhytisma. The most common species are Rhytisma acerinum and R. punctatum. Symptoms first appear in late spring or early summer as infected leaves develop light green or yellow-green spots. During mid to late summer these produce black tar-like raised structures on the upper surface of leaves within the yellow spots. R. acerinum causes larger spots that are 0.5 to 2 cm in diameter; R.punctatum causes many small[Read More…]
Should I stake my tree after planting it? The answer is “no” for most situations, however, there are circumstances which require some support for a newly-planted tree to get it off to a good start.
Timing of defoliation, health, and type of tree influences the likelihood of recovery and survival
The Tree Care Industry Association (TCIA) conducted an analysis of 62 civilian tree care-related accidents reported by the media from January 2017 to June 2018. TCIA is a trade association that promotes professional tree care and discourages homeowners from taking unnecessary risks caring for their trees themselves. While these numbers are not representative of all – or even most – tree care accidents involving non-professionals, they provide insight into the types of hazards homeowners are likely to encounter while attempting tree work. The findings were grim: Forty-one of the accidents (66 percent) were fatal. “Homeowners may not realize how dangerous tree work can be, and how much they’re risking by taking the ‘do-it-yourself’ approach,” says Peter Gerstenberger, senior advisor for safety, standards and compliance for TCIA. “Lack of training, equipment or situational awareness undoubtedly contributed to these incidents, which could have been avoided by hiring a professional tree care[Read More…]