Wednesday, June 3, 2015

Donations Needed For Azalea Lace Bug Devastating Medians In Neighborhood

This information was recently included the Laurelhurst Newsletter, published by the Laurelhurst Community Club:

Image result for picture of lace bug

Azalea Lace Bug Devastates Medians
Community Contributions Sought
Years ago, LCC negotiated agreements with the University of Washington and Talaris to maintain the median planting beds on Mary Gates Way and NE 41st St. with each caring for about one-third of the lengthy stretch of median. Two things happened. The UW was no longer able to continue its share of the maintenance due to severe budget cuts and Talaris discontinued its maintenance. LCC has contracted with a private landscaping company to prune, weed, and mulch the beds and service the irrigation system. Neighbors have assisted in this effort.
Now these planted medians are looking pretty rough due to a very serious azalea lace bug infestation on all the Rhododendron ‘Cilpinense’ planted there. UWBG horticulture staff currently are dealing with serious outbreaks in the arboretum and some at CUH as well.
LCC trustees Emily Dexter, Liz Ogden, and Jeannie Hale have teamed up to research plantings and solicit bids from several landscapers for replacement of the beloved Rhodendrens, which experts recommend removing. Heath Landscape, with whom LCC currently retains a maintenance contract for the medians, suggests planting clusters of Lavender, small varieties of Ceanothus, and Baggesens Gold Lonicera as replacements.

Plant expert Arthur Lee Jacobsen recommends, Ceanothus, Euonymus japonicus, Grevillea victoriae, Lagerstroemia (dwarf selections), Leptospermum. Heath provided a bid of $7,000 to remove existing plants, prepare the soil, replant with English Lavender, Ceanothus, and Lonicera Bagessen’s Gold, and mulch. Replacement of the old sprinkler system would be an additional $2,400.
LCC is seeking additional bids and is working hard to formulate a plan to restore the once-beautiful medians. Additional contributions to LCC’s Landscape Fund are always welcome and appreciated. For more information on lacebug infestation go here.
LCC contacted Raymond J. Larson, Curator of Living Collections, University of Washington Botanic Gardens, about the lace bug infestation, and he graciously responded with the following comments. “Yes, we are having the same problem at the Arboretum and I also noted it the last two years at the [UW] president’s residence.

Azalea lace bug is new pest to our area, apparently first appearing around 2010. But it has been in the southeast US for a number of years before that, after arriving from Europe. It is very difficult to control, as the insect has many generations a year and builds up populations very quickly. We have long had “Rhododendron lace bug” but that insect only produces one generation a year and is far less damaging.
“We’ve been treating the most severely affected plants in the Arboretum with limited success. ...We have been spraying them monthly for the last couple of years but it hasn’t made much of a difference, and we are cutting some back now and removing others. While not immediately fatal, it does weaken the plant over time and can lead to death. I’m guessing it was on the median plants before last year, but the populations have built up to be more noticeable and new leaves are affected quickly.
“The median is a stressful environment for plants, due to the reflected heat and depleted soil (after 20 years) as well as the intense light and traffic impacts. The R. ‘Cilpinense’ has a finite lifespan and the Azalea lace bug is adding to its decline.

Most Rhododendrons cannot tolerate as much heat and light as R. ‘Cilpinense’ receives out there, but it worked for many years. I think one of the reasons the northern-most median along Mary Gates Memorial Drive looks as good as it has compared to the other islands is because it was in more favorable light conditions.
A neighbor commented “...we do appreciate the LCC’s efforts to create and maintain such an attractive entrance to the neighborhood. It has long been one of the most attractive median plantings in the city.”

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