Boxwood Blight Update
October 2, 2015
The past 8 days have included 6 days of rain, one cloudy day, and one sunny day. In that period, we had nearly 6 inches of rain. Our forecast is for 3 more days of possible heavy rain. The temperature has been hanging between 60 and 80 every day. This is the perfect storm for a boxwood blight outbreak (prolonged periods of rain and cool temps). With all of this on my mind, I thought it was time to update you on what we have learned recently with regard to boxwood blight.
Over the past several months, I have had the unfortunate opportunity to talk to about a half dozen people who have witnessed the blight first hand either in landscapes or garden centers. I actually appreciate the discussions that I get to have. With each encounter I feel I learn more about the disease. Here are some of my thoughts:
The disease had been introduced to the landscape or plants and didn’t just spontaneously appear. Some of those trails were much clearer than others.
Everyone needs to be careful about cleaning tools if they are used in multiple landscapes especially around boxwood.
In all cases, sempervirens cultivars have been infected. Most commonly ‘Suffruticosa’ (English Boxwood).
Yellowing and browning on leaves and sections of English boxwood is, much more often than not, in no way related to boxwood blight. I get calls and emails regularly from individuals who panic and assume the sick plant has ‘the blight’.
One researcher is using an infected landscape to test and observe infected mature plants.
It is very encouraging to hear that the USDA has put a significant emphasis on boxwood blight and they have several labs doing work on it. DNA is being mapped on many varieties of boxwood and that information is being used to predict varietal tolerance in existing varieties as well as assist in identifying beneficial traits for boxwood breeding programs. An interesting thing that seems to be coming out of the DNA is the fact that the variety ‘Justin Brouwers’ is most likely going to be switched into the sempervirens family. A researcher in Europe told us this a while back and now the US labs are agreeing.
At our nursery, we are considering implementing additional protocol to delay the introduction of the disease as well as minimize the movement of the disease. We will continue to limit non-staff access to production areas. We have installed foot baths at the entrances to our office. (Please use them when you stop by.) We are discussing ways to minimize the number of times our staff enter boxwood production areas. We are looking at ways to economically and efficiently clean our equipment more often. While we realize some of the protocol we have enacted can be slightly bothersome when visiting or purchasing, we are thankful for the understanding that nearly every customer or visitor has had when visiting the nursery. As I have mentioned before, we don’t doubt that one day we will see the disease, however the further we are down the road from that time the smarter and more prepared we will be.
Someone asked me the other day how I felt about boxwood blight. I remember getting the call in October of 2011 from a nurseryman telling me about seeing the disease firsthand and its destruction. I (and the rest of Saunders Brothers) went into freak out mode thinking near ‘end of the world’ scenarios. Nearly 4 years have passed since that call and we have moved from freak out mode to a mode of deep respect. We (the nursery industry) will learn to manage this disease by using tolerant varieties and better management practices both in the landscape and in production.
Happy fall gardening and I hope we see the sun very soon.
The latest update on the boxwood blight from Saunders Brothers, Inc.
Best Management Practices - Feb. 24, 2012
A New Disease for Connecticut and the USA 12-08-2011
Symptoms CT 12-08-2011