Ornamental dogwoods are prone to several leaf spot diseases, but the fungus, Septoria, is commonly found in Indiana.  It causes angular, brown lesions bordered by a purplish color on the leaf.  The leaf spot symptoms are similar to dogwood anthracnose, however, Septoria does not infect the twigs or branches so it is a much less…Read more about Septoria Leaf Spot on Dogwood[Read More]

Fragrant sumac (Rhus aromatica) is a low growing native shrub that is valued for its adaptability to many soil types, wet or dry conditions, easy care as a ground cover, and for preventing erosion on slopes. It is often found in highway medians (Fig. 1), in parks or as a foundation planting around commercial buildings….Read more about Fragrant Sumac Succumbs to Fusarium Wilt[Read More]

“We never look deeply into the quality of a tree; we never really touch it, feel its solidity, its rough bark, and hear the sound that is part of the tree. Not the sound of wind through the leaves, not the breeze of a morning that flutters the leaves, but its own sound, the sound…Read more about Root Rot[Read More]

Although most cities contain an Elm Street, very few cities can claim having mature American elms on that street, or any other. The American elm was a premier street tree: Tolerant of compacted soil, fast growing, long-lived, and with a beautiful vase-shaped form. It’s very popularity led to its downfall. The introduction of Dutch elm…Read more about Dutch Elm Disease[Read More]

Like anthracnose diseases of other shade trees, sycamore anthracnose is a very common occurrence in the landscape (Figure 1). Symptoms of sycamore anthracnose normally develop as small spots or dead areas centered along the veins of leaves or along leaf margins (Figure 2). Under conducive conditions these spots expand, killing more leaf tissue and causing…Read more about Sycamore Anthracnose – Don’t let the rains get you down[Read More]

Introduction The Colorado Blue spruce is not native to Indiana and tends to be susceptible to disease.  One common disease, caused by the fungus Rizosphaera kalkhoffii, results in the defoliation of the tree.  If left untreated needlecast can lead to the death of the tree. Symptoms and Signs Symptoms of needlecast don’t develop until two…Read more about Needlecast in Colorado Blue Spruce[Read More]

Although most people are understandably concerned about boxwood blight, boxwood does suffer from a number of diseases, including Volutella blight and Macrophoma leaf spot. Unfortunately, boxwood also suffers from a stem decline, caused by Colletotrichum theobromicola. The following was written by Dr. Raj Singh, LSU. Boxwood Stem Decline by Dr. Raj Singh Available on line…Read more about Other Boxwood Issues[Read More]

Oak leaf blister is caused by the fungus Taphrina caerulescens.  Infections occur as buds swell and open during wet, spring conditions. Leaf blister symptoms usually appear within several weeks following infection as 1/4-1/2 inch circular, light green bulges on the top surface of leaves.(Fig 1) From the underside, the affected areas are sunken or depressed. These…Read more about Oak Leaf Blister – No Cause for Concern[Read More]