I first raised the alarm on boxwood leafminers (Monarthropalpus flavus) in a BYGL Alert posted in late March (see "Blistered Boxwoods and Hissing Hedges", March 30, 2017). That report focused on alerting landscape managers that high localized populations were producing heavy leafmining symptoms that could be mistaken for winter injury.

The crabapple plot, called Crablandia in Secrest Arboretum, is located in Wooster, Ohio and will be in full bloom and full splendor, in the next couple of days.  With the onset of multiple periods of unseasonably warm weather, the typical bloom emergence time is about 2 weeks ahead of schedule.  The incredible display of crabapple flowers has traditionally been one of the most popular times to stroll through the Arboretum and experience the amazing fragrance, accompanied by marvelous views of flower petals.

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Last week, while photographing calico scale (Eulecanium cerasorum) on honeylocusts (Gleditsia triacanthos) in a commercial landscape (see BYGYL Alert, Calico Scale is Puffing-Up and Pumping Honeydew, April 19, 2017), I came across two trees with numerous knot-like growths on the stems.

Junipers in southwest Ohio are being garnished with tangerine tentacles and orange goo; the calling cards of rust fungi. The three fungi producing the colorful displays belong to the genus Gymnosporangium and each must alternate between a member of the plant genus Juniperus and members of the rose family (Rosaceae) in order to complete their life cycle.

Wilting buckeyes may sound like an Ann Arbor dream, but I'm not talking about our beloved Silver Bullets. I'm referring to the symptoms caused by the Buckeye Petiole Borer (Zeiraphera claypoleana) on its namesake host.

Overwintered calico scale (Eulecanium cerasorum) females are now "puffing-up" and pumping out impressive quantities of clear, sugary honeydew in southwest Ohio. The appearance of the globular, helmet-shaped females coupled with complaints of trees oozing sticky goo makes this life-stage important for detecting new infestations. All other life-stages are much less obvious.

Common Chickweed (Stellaria media) is a European winter annual that is now found world-wide. Winter annuals are sneaky weeds. They produce seeds in the spring then plants fade away prior to the summer season; out of sight, out of mind. The seeds dodge spring applied preemergent herbicide bullets because they do not germinate until the fall. The resulting plants grow below our radar throughout the fall, winter, and early spring when we pay little attention to what's going on in our lawns and landscapes.

Poison Hemlock (Conium maculatum) is one of the deadliest plants in North America. This non-native invasive was imported as an ornamental in the late 1800s from Europe, West Asia, and North Africa. The plant contains highly toxic piperidine alkaloid compounds, including coniine and gamma-coniceine, which cause respiratory failure and death in mammals.

I've watched Cressleaf Groundsel (Packera glabella; syn. Senecio glabellus) for years popping-up in landscapes and farm fields. However, I never truly appreciated the canary yellow display provided by this winter annual. Indeed, I've placed all of my past BYGL reports on this native plant under the header, "Weed of the Week."