Gray mold (causal agent = Botrytis cinerea) is one of the most common diseases affecting bedding plants. Host commonly include (but are not limited to): begonia, carnation, chrysanthemum, cyclamen, geranium, impatiens, marigold, million bells, petunia, vinca and zinnia. Fortunately, gray mold is one of the easiest diseases to manage. By changing cultural conditions that are[Read More…]
Janna Beckerman
A mild winter, followed by a brief warm-up, caused many plants to flower or leaf out before one last freeze. Unfortunately, that succulent new growth is much more susceptible to frost and freeze damage. Freeze injury in many plants will occur when the temperature falls below 32° F (0° C) and the water within the[Read More…]
Earthworms are not the only wigglers in the soil beneath your feet. Nematodes, microscopic roundworms, can be found in soil across the globe (even Antarctica!) and are often a barometer of soil and environmental health. However, the nematodes we encounter more frequently feed on plants and cause us, as plant stock producers and consumers, a[Read More…]
Day-to-day activities have changed every aspect of businesses throughout the country. The Green Industry is no exception, with changes implemented to maintain safe working environments for employees and their clients while being compliant with the state’s Executive Order. Due to the diversity of services and products that the Green Industry provides, there is no one-size-fits-all[Read More…]
Plant pathology is the study of plant diseases. In my career, I’ve studied or witnessed the plant disease epidemics of chestnut blight, Dutch elm disease, sudden oak death, soybean rust, and many more. I am not comparing these to the current pandemic of Covid-19. It doesn’t compare. Please understand this is just an opportunity for[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…]
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…]
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…]
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…]
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…]
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…]
Fungal diseases of ornamentals will always be a limitation to profitable plant production and management—how significant that limitation is in your hands. Fungicides are effective in reducing the risk of loss– in numbers, in quality and in terms of aesthetics. However, fungicide costs in terms of product cost, number of applications and labor need to[Read More…]
Diseases that affect the twigs, branches, and the main trunk of a tree are referred to as cankers or blights. Cankers appear as a general sunken area of darkened tissue on the twigs or branches, often surrounding a branch stub (Fig. 1). Canker diseases can be a serious problem in the landscape when they are[Read More…]
Fungi are a unique group of organisms—so unique that they are put into a separate category called a ‘Kingdom’. In Kingdom Fungi, some members cause rust, scab, powdery mildew, leaf spots and blights (to name but a few!). When these fungi are ‘out of control’ many people turn to fungicides. What are fungicides and how[Read More…]
Xanthomonas is both an unfortunate, but regular occurrence in the greenhouse industry. Despite the efforts from numerous companies to supply ‘clean plants’, Xanthomonas (and other bacterial pathogens) regularly slip through. This year, it came in on begonia. The pathogen. Xanthomonas is a genus of yellow colored bacteria that infect many species of plants (approximately 400!),[Read More…]
Colorado blue spruce is not native to Indiana (no spruce is!), and it often suffers from environmental stresses such as drought, excessive heat, humidity, and compacted or heavy clay soils—making it an already poor choice for our landscape. If that weren’t enough, it also suffers from needle cast diseases. Needle cast is a generic term[Read More…]
This is the time of year when growers begin planting seed—whether you are child planting a few seeds in Dixie cup for a school project, home tomato growers, or professional horticulturists. Unfortunately, one problem you may share in common is damping-off. Damping-off describes the death of seeds or seedlings and includes all of the following[Read More…]
