As we finally begin to experience some hot weather this summer it’s a good time to take stock of predominant local tree issues. We’re seeing continued Ambrosia beetle activity (please see below.) With another year of experience, we’ve learned more about this dangerous predator’s appetites. Although last year we actually saw the ambrosia beetle in pine trees, in general they were most common in thin-skinned trees, like maples. This year we’re also seeing them more frequently in figs and crapes. If you catch the infestation early, we can try to treat that tree and spray surrounding thin-skinned trees with an insecticide. But it’s always safest to remove any tree with ambrosia beetles, AND spray the surrounding trees.
Because Leyland Cypresses are so over-planted in the Atlanta metro area, they have always been prone to fungal infections, particularly bot and seridium cankers. These have been fairly easy to manage. Because they affect the branch tips and move inward, we prune the affected branches back to live wood and try to get the tree healthy. An unhealthy tree is always most prone to problems. We began noticing late summer, 2013, a new problem affecting Leylands. The branches had the same orange discoloration, but they were spreading from the inside out. And the infections don’t affect just a few random branches, but most of the branches. So pruning is not an option. We thought we were seeing a type of cercospora needle blight. The only remedy is a series of fungicidal sprays.
We have seen a lot of this condition this summer, and we now have a more accurate diagnosis. It’s actully a type of cercospora called passalora needle blight. If you look inside your Leyland and it seems to glow orange, unfortunately you probably have it. If you do nothing, the entire inside of your tree will die back and the needles will fall off. The impression is that you have a hollow tree. Which makes trimming back the branch ends impossible. The control reccomended is a series of fungicidal sprays and as always we reccomend a root invigoration to boost the tree’s immune system.
There is no ‘cure’ for passalora. If a mature tree is completely affected, you should probably remove it to try to limit the spread of the disease and to avoid expensive and unproven treatments. The Clemson web site offers more helpful information: http://www.clemson.edu/extension/hgic/pests/plant_pests/trees/hgic2004.html.
Late Summer and Fall of 2013, we noticed a lot of Turpentine Beetle activity in Atlanta area pine trees. Of all the beetles infesting pines, these are easiest to treat — if you notice them early. They produce very large pitch tubes on the lower trunks. Please see photo. If you see the crystallized sap on the sides of your pines, please call for a free assessment. You may save not only this tree but other nearby pines as well.
For most of 2013, the primary antagonist was the Ambrosia Beetle. This is an extremely dangerous pest which is very easy to spot.
07 / 20 / 2015
Please check new information posted in our recent Blog about the Emerald Ash Borer (EAB). This may be the most hazardous threat to Atlanta trees.