Conifers Are Cratering

Junipers in a commercial planting are dying within 10 months of being planted. What’s going on here?

I’m getting tons of questions about Italian cypress, Blue Point junipers and other related plants that are turning brown section by section, usually starting at the tips of the plants and quickly working their way back down large branches.

Gardeners try to prune out the dead wood, but the plants are so symmetrical by their nature that it pretty well destroys their beauty.

Seiridium canker has just about ruined Leyland cypress as a landscape plant for Texas and beyond.

The purpose of this note is to (1) let you know what the problem is and, perhaps (2) encourage you to find alternative plants that won’t be susceptible to these same diseases.

Italian cypress in Karnes County, as photographed and posted on my Facebook page by Teresa G. Seiridium canker is having its way with this plant.

Seiridium canker is responsible for many of the thousands of trees that have been, or will be, lost. It causes entire branches to turn brown. On closer inspection you’ll see a black ooze running down the trunk of an infected tree, and by that time there is no turning back. Pruning simply won’t help.

Continued Below

Phomopsis blight is common on many of the junipers. It shows up at the tips of the branches, killing the shoots back from those points. Pruning and fungicides help more with this disease than they do with Seiridium canker, although that’s not saying a lot.

Without sending these plant samples through the Texas A&M Plant Disease Clinic, it’s difficult to tell which malady is bothering your plants. This photo from Steve and Shonda H. shows twig dieback of Italian cypress. That’s more in keeping with Botryosphaeria canker.

Wet springs like we’ve been having are prime times for these diseases, and true to form, we’re seeing a lot of each of them.

This Fact Sheet from Texas A&M is excellent, and you’ll find other great information from other southern Land Grant universities with just a little Internet searching.

Posted by Neil Sperry
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