Question of the Week 1: April 6, 2017
“Neil, is it possible there is anything else besides spider mites killing Italian cypress?”
Junipers and Italian cypress are quite susceptible to spider mites. I’ve been watching them have troubles this spring. In fact, a shrub-form of juniper I am growing in a large container in my own landscape was loaded with mites just two weeks ago.
So that’s where I headed when people started asking about their Italian cypress 10 or 15 days ago. That was the main focus of my answer to last week’s Question of the Week.
However, I’ve been across a lot more miles these past seven days and I’ve seen a ton of more serious dieback like what you see in this photo.
Photo: This is Seridium Canker killing big sections of Italian cypress trees in North Texas. You may recall the same organism almost eliminating Leyland cypress from landscapes in much of the state several years ago.
My good friend Russell Peters of Arborilogical Services of DFW (and a former Arborist of the Year for the entire state of Texas) wrote to me last weekend to say that they have encountered a good bit of two disease organisms. Russ got his Master’s Degree in Plant Pathology, so when Russ speaks, I listen. Here is what he wrote:
“We have gotten both Seridium Canker and Phomopsis Tip Blight isolated from Italian Cypress that appear as your photo. Granted, with little killing temperatures this winter, our mite populations have simply continued feeding right on through to the spring.
But we also see a fairly regular occurrence of those two fungal pathogens. I can forward a copy of the A&M Lab report if you would like a copy. It is from tissue collected from a tree in Coppell and sent in with a few of the partially dying lateral limbs and the 2- to 4-inch dead tips. We also see Seridium isolated from those trees that die from the ground up.
Italian Cypress trees are apparently really sensitive to being planted too deeply or, more often the case, the root collar gets buried over time. This results in stress that usually contributes to the plants performing poorly.”
Russ continued to think about this topic and wrote just a little later, “I also believe that the 14 degree +- night or two stressed them badly, as they are marginally suited long-term here (in DFW).”
And when I asked him what Arborilogical Services offers as means of dealing with these two very challenged diseases, he wrote back, “We do not offer any management options. It’s unfortunately one of those problems for which we offer accurate diagnosis but no management tactics.”
So this is not good news, but at least it offers better definition of the problem.
For the record, Arborilogical Services is an advertiser in this newsletter, on my website and on my radio program.