Knowledgebase

Leland cypress trees #482154

Asked August 31, 2018, 7:03 PM EDT

We had to cut down 12 dead Leland cypress trees this last spring due to what we think is a beetle problem. They were in a line along the back border of our property, and have 6 left of that variety. The remaining 6 have a lot of dead tips, like 6 to 12 inches at the very tip of the branch is brown and hangs down. We were told they might be able to be saved if we contacted a company that specializes in pest spraying. Ive hunted around with no luck and was hoping you may know of anyone. We also have 77 Leland’s that shield our property from the road which we are most concerned about losing. They are a different variety called “castle weyland” and up until now I hadn’t noticed the tip death problem on those, but I see now some do. The 12 we cut down had the tip death last year then all of a sudden this spring the whole tree turned brown and was dead in what seemed like maybe a month. Have you heard of these specific symptoms? If so is it beetles? Do you know if there is an effective spray for this? I would imagine having 77 + 6 trees sprayed would cost a lot... worth it as long as it’s not a waste of time. I’ve heard differing opinions on the subject, and am hoping someone could shed an educated opinion as well.

Josephine County Oregon

Expert Response

Diseases that result in browning of Leyland cypress often occur on stressed, weakened trees. Providing the right care is many times all the prevention needed to maintain healthy cypresses. Leyland cypress grow best where they get full sun to partial shade. With a preference for moist, well-drained soil with good fertility, Leyland cypresses will continue to develop well under most conditions, including acid or alkaline soils and occasionally wet soil.

This could be a sign of a fungus called Seiridium cardinale (formerly Coryneum cardinale. Symptoms include old foliage that yellows and browns in spring, followed by a fading green or death of new foliage. Small branches are infected first, then larger ones. A typical lens-shape, sunken canker can be found on the branch below affected foliage. Top death and dieback are common. Bark turns brown, and small, black fruiting bodies (acervuli) may form in the cankered area. Drops of resin frequently are in and at the sides of cankers. The expansion of cankers is slow on large branches and trunks of mature trees. Could be confused with Monochaetia canker.

Cultural control

  • Plant resistant cultivars.
  • Remove and destroy affected branches 1 to 2 ft below the canker. Sanitize pruning tools between cuts.
  • Avoid water stress and wounding trees.

Here are a couple of publications that may help.

https://pnwhandbooks.org/plantdisease/host-disease/cypress-cupressus-spp-canker

https://www.uaex.edu/publications/pdf/FSA-7536.pdf

Hope this helps!

Chris Rusch Replied September 05, 2018, 12:33 AM EDT

Loading ...