Cherry, plum, almond, peach and cherry laurel all get a common issue called shot hole leaf spot. At first, a chlorotic or necrotic spot develops on the foliage (Figure 1). When a tree has severe symptoms, the leaves may drop prematurely from the tree. If the leaves remain on the tree, the leaves produce a[Read More…]
Resources for landscapes and gardens in the Midwest
Landscape Report
Trees, Shrubs, Vines
Yews are widely used as foundation plantings in many areas and are valued for their dark, evergreen foliage. The most widely used landscape yews are Japanese yew (Taxus cuspidata) and Taxus x media hybrids, such as Hicksii or Wardii Yew. While few diseases and insects attack yew, there are a few problems to watch for.[Read More…]
Diagnosing abiotic (non-living) problems in plants can be challenging due to the many interacting factors and varying levels of plant tolerance. In many cases, reviewing the recent weather history of a given area provides valuable insight into the possible causes of observed symptoms. Over the past few weeks, several samples submitted to the Purdue Plant[Read More…]
Tree care, in many cases, can be expensive if you require the assistance of an arborist for pruning or removals. Extreme weather events, characterized by extensive rain and wind, can cause damage to the canopy or, in worst-case scenarios, lead to tree failure. In cases of failures, weather is often the final push to already[Read More…]
These three maples have somewhat similar-looking leaves. On the surface, you may think this is simply an academic exercise. But if you care about invasive plants and local ecology, this distinction is an important one. Norway maple is an invasive tree species, while sugar and black maples are native tree species (sometimes called hard maples).[Read More…]
Sawflies are frequent pests in the landscape that attack a wide variety of plants, from ornamental flowers to large trees. You might start to see them damaging plants around this time of year as the first generations hatch and begin to feed on foliage. They are often mistaken for caterpillars, which are the larval stages[Read More…]
Recently, there has been an uptick in questions related to one of Indiana’s most notorious invasive pests: the emerald ash borer. Homeowners, businesses, even professionals have asked if ash trees are still present in Indiana, and if the insect is still a threat to our ecosystem. Emerald ash borer wreaked significant havoc among Indiana’s hardwoods,[Read More…]
During a nursery inspection in Owen County in 2024, I noticed an unusual yellowing of the leaves on some American Hornbeam (Carpinus caroliniana) trees (Fig 1). A look at the underside of the leaves revealed yellow-orange pustules, suggesting a rust fungus. After help from the Purdue Plant & Pest Diagnostic Lab, this fungal pathogen was[Read More…]
Hypoxylon canker is a common disease of mature hardwood trees both in landscapes and in natural wooded areas. The disease, caused by the wood decay fungus Biscogniauxia (formerly Hypoxylon), is most frequently observed in oak tree species, but can also cause dieback in pecan, hickory, golden rain tree, sycamore, maple, beech, birch, elm, willow, basswood,[Read More…]
Spring is finally here! Everywhere you look, one can find some spring color around. Some of the first plants to peek out of the ground are spring-flowering bulbs like crocus, daffodil, and tulip. But there are some beautiful spring time shrubs you can add to your yard to be the first in the neighborhood with[Read More…]
A perennial edible garden offers an opportunity to integrate beauty and utility. By incorporating fruit trees, berry bushes, and other long-lived edible plants, the home landscape can be both aesthetically pleasing and agriculturally productive. A perennial edible garden not only provides seasonal harvests but also supports local biodiversity. Plan(t) for Success Careful planning and site[Read More…]
Plants that show little growth, are stunted, or are wilted and in active decline are all hallmarks of root stress. Some of the more prominent pathogens that cause root rot include Fusarium, Phytophthora, Pythium, and Rhizoctonia, but there is another fungus which can cause just as much damage in the right situation that does not[Read More…]
April showers bring May Flowers. Many of us were taught this little rhyme to describe the weather of Spring. April has arrived along with the beginning of the Spring storm season and damage to and from trees is a topic of concern on many minds. Depending on the intensity of the storms and the condition[Read More…]
Some of you may recall news in 2020 about unsolicited seeds being sent in the mail from overseas (https://www.purdue.edu/newsroom/archive/releases/2020/Q3/unsolicited-seeds-could-wreak-havoc-on-agriculture,-environment,-state-officials-warn.html). There have now been recent reports of this happening again. Ric Bessin, Entomology Extension Specialist, and Joe Collins, Deputy State Entomologist, from the University of Kentucky, wrote about reports of unsolicited seeds from the south,[Read More…]
These oak trees are showing the symptoms of smooth patch (Figures 1, 2, 3). This condition is the result of a fungal infection that is restricted to the outer bark, causing it to slough off. The bark layer remaining is smoother and lighter in color than uninfected, normal bark. Patches can vary from a few[Read More…]
Recently, white prunicola scales (Pseudaulacaspis prunicola) were detected on Prunus during a DNR nursery inspection. This is a significant scale pest of woody ornamentals and fruit trees in eastern states, but it is currently not established in Indiana. It is primarily a pest of cherry, lilac, and privet species. Its total reported host range spans[Read More…]
We have received a few elm tree samples this year with a disease we do not often see, but which is relatively common: black spot of elm. This disease, also called elm anthracnose, is caused by the fungus Stegophora ulmea and can affect most species of elm with American elm varieties being more susceptible. The[Read More…]
August was National Check Your Tree Month, but this is something that every tree owner/manager should be doing year-round. As the last hot days of summer are finishing up and we look forward to cooler fall days, we can look to our trees for different signs of trouble. Most people tend to look up at[Read More…]
In the last newsletter, an article on triclopyr (www.purduelandscapereport.org/article/the-summer-of-triclopyr-mounting-evidence-for-off-target-damage/) brought up much discussion on the Roundup brands now containing multiple active ingredients other than glyphosate. Professionals in the industry may encounter a client with herbicide damage symptoms that mimic growth-regulator injury instead of typical glyphosate damage symptoms. While the client may have used Roundup, they[Read More…]
There have been a significant number of questions and problems regarding triclopyr that have come across my desk this growing season. Several of these problems have come through the Purdue Plant and Pest Diagnostic Laboratory (https://ag.purdue.edu/department/btny/ppdl/index.html) from landscapers, nurseries, and property managers. General Information about Triclopyr Triclopyr is a selective systemic herbicide belonging to the[Read More…]
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