This Nootka falsecypress (Chamaecyparis nootkatensis) is showing severe dieback throughout much of the tree (fig. 1 and 2). The primary pathogen present is a fungus in the genus Diplodia. Small twigs are infected first, which eventually leads to dieback of larger branches (fig. 3). Note the spherical black spore bearing structures (pycnidia) at the base[Read More…]
Resources for landscapes and gardens in the Midwest
Landscape Report
Plant Diseases
The dead lower branches in these Austrian pines (Fig. 1) are due to Diplodia (= Sphaeropsis) tip blight. The causal fungus infects newly elongating shoots, in late spring, resulting in stunting and death of the new growth (Fig. 2). Black spore-bearing structures of the causal fungus are formed at the base of the stunted brown[Read More…]
A workhorse of the shade garden, impatiens, also called ‘Busy Lizzies’ delight people by their amazing ability to brighten up shady sites. Downy mildew, caused by the water mold Plasmopara obducens put a damper on things for almost a decade. This downy mildew infects impatiens (Impatiens walleriana), or balsam impatiens (Impatiens basamina). New Guinea impatiens and[Read More…]
The 2019 season provided challenges that were unexpected to the Green Industry, which included an abundance of rainfall followed by drought-like conditions, new invasive pests, concerns about glyphosate use, and many others. The Purdue Landscape Report focuses on timely articles that help Green Industry professionals make decisions for their business and keep abreast of looming[Read More…]
Hunting for mushrooms is a fun past-time, even if you are not looking for edible fungi to “spice” up your cooking. However, when you see a fungal invader popping up in your lawn or landscape, they tend to be unwelcome inhabitants because they are launching sticky spore masses onto your siding, producing foul odors (Figure[Read More…]
If your hostas are looking a little ratty recently you’re not alone (all the photos here are from my garden). Hostas at this time of year tend to have marginal scorch, dieback, leaf spotting and yellowing . A variety of factors may contribute to these symptoms including environment, diseases and insect pests. Anthracnose, caused by[Read More…]
White mold, caused by the fungus Sclerotinia sclerotiorum, is a specific fungal pathogen that infects several hundred species of plants from more than 75 different families, resulting in death of the infected plant (Fig. 1). Many of the most popular annuals and perennial plants have been reported to be susceptible to white mold, from aster (Aster[Read More…]
You are invited to attend this free educational opportunity on campus or via webinar to this event on October 23rd! If you are interested in attending in person, please contact Kyle Daniel at daniel38@purdue.edu for details. Title: The Changing Nursery Industry: How Will You Adapt? Date: Wednesday, October 23, 2:30-5:15 PM, EDT Moderator:[Read More…]
Have you ever noticed the fuzzy growth (Fig1) on the underside of an oak or sycamore leaf and wondered what was wrong with the tree? Fuzzy mats of hairy growth on the underside of tree leaves (Fig 2) are often mistaken for a plant disease or insect problem. In actuality, the whitish-tan fuzzy growth is[Read More…]
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…]
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…]
From Matthew Chappell, UGA NewGen Boxwood, marketed by Saunders Genetics, LLC, will unveil the first two introductions in its groundbreaking boxwood program at Cultivate’19. The two exclusive varieties will be available in the marketplace beginning early 2020. The revolutionary aspect of the brand-new introductions is reflected in the given names—Buxus NewGen Independence and Buxus NewGen[Read More…]
Don’t miss the 2019 Purdue Turf and Landscape Field Day on July 9th! Your opportunity to interact with Purdue Specialists, see the latest on-going research and best management practices, and network with others in the Green Industry. This is the premiere Green Industry education event that you’ll find this summer! https://www.mrtf.org/event/turf-and-landscape-field-day/?event_date=2019-07-09 In the landscape track,[Read More…]
The Cooperative Extension Service is a national network of land-grant colleges, universities, and the United States Department of Agriculture serving communities across the country by providing research-based information and educational programming. Purdue Extension serves Indiana residents in the following program areas: Agriculture and Natural Resources, Health and Human Sciences, Community Development, and 4-H Youth Development.[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…]
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…]
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…]
Sudden oak death, as the name suggests, is a disease that is capable of rapidly killing certain species of oaks. It was first identified in California, in 1995. Two years earlier it was identified in Germany and the Netherlands, killing rhododendron. Because the pathogen originally infected and killed tanoaks, an undesirable, understory scrub tree, it[Read More…]
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