Nursery & Forest
Volume 57 Number 7 Date 05/24/2012
INVASIVE SPECIES RULE - Nursery inspectors report that the invasive ornamentals Ampelopsis brevipedunculata 'Elegans' (variegated porcelain berry), Leymus arenarius (blue lyme grass), Nymphoides peltata (yellow floating heart) and Hesperis matronalis (dame's rocket) were being offered for sale at nurseries and garden centers in Bayfield, Ozaukee and Sauk counties. Under the Chapter NR 40 Wisconsin Invasive Species Rule, it is illegal to transport, import, transfer, sell or introduce any species included in the rule's prohibited or restricted categories. It is important for nursery operators and brokers to become familiar with these species because some may be available from out-of-state sources. Refer to the following website for a list of Chapter NR 40 invasive species: http://dnr.wi.gov/topic/invasives/classification.html
ANTHRACNOSE - This fungal leaf spot disease of many herbaceous and woody plants is reported to be infecting hostas in Kenosha, Milwaukee and Racine counties. Anthracnose is the most widespread foliar disease of hosta. Symptoms vary by host plant, but typically appear as irregular necrotic spots with dark borders that merge to form large dead areas. No corrective action is needed, aside from disposing of infected leaf litter and debris to reduce inoculum sources.
COLUMBINE LEAFMINER - Leaf mines caused by the larval stages of this insect were noted this week on columbine in a Marquette County nursery. The serpentine mines initially appear whitish in color and eventually turn tan or brown later in the season. Removing and destroying infested leaves will reduce this aesthetic problem.
-- Liz Meils, DATCP Nursery Inspector
GYPSY MOTH - Gypsy moth Btk treatments totaling 9,158 acres were applied from May 17-22 in Barron, Bayfield, Burnett, Chippewa, Douglas, Dunn, Polk, Rusk and Sawyer counties. The Wisconsin DNR's Gypsy Moth Suppression Program also treated 196 acres on the property of Governor Thompson Centennial State Park in Marinette County on May 17. A second application of Btk is tentatively scheduled for May 29 in Bayfield, Douglas and Sawyer counties on approximately 2,347 acres. Spraying has ended for the year in Barron, Burnett, Chippewa, Clark, Grant, Green, Iowa, Lafayette, Marinette and Polk counties.
-- Nkauj Vang, DATCP Gypsy Moth Program