Evergreen trees are a beautiful addition to landscapes. They provide year-long screening for privacy and also help to reduce winter winds. There are dozens of common varieties of evergreen trees found here in Lancaster, PA on both residential and commercial properties that we service both as professional landscapers and to maintain with our tree service. These functional native plants are a favorite of many and great plants to consider if you are planning your landscape design. However, before you or a landscape designer select a specific variety for your property, be sure to research the disease, insect, and mite issues each plant may face in their lifetime. There is no plant that is immune to issues. Some will be lower maintenance than others, but each comes with its own challenges that you should carefully plan to address from a proactive standpoint.
One of the common issues with a lot of varieties of evergreen trees, particularly Pines, Firs, Douglas Firs, and Spruces are diseases called Needlecast diseases. These diseases are caused by fungi and cause browning, spotting, and tissue distortion. The infected needles will generally change their appearance and fall several months after the time they become infected with the disease-causing fungi. Infection time varies by species and weather conditions, but is most common during late spring and early summer months when new growth is emerging from the buds of the evergreen tree. It is then when fungi develop very small fruiting structures on the needles. These fungal structures are extremely difficult, and most times impossible to see without magnification. They can appear as tan, black, orange, or red spots or stripes depending upon which Needlecast you are seeing. Poor air circulation, and moist, warm conditions during the new growth’s emergence provides the ideal conditions for growth of these fungi.
It isn’t until the following winter, spring, and next summer that symptoms such as browning, spotting, and distortion will occur. At that point, spraying trees for disease is pointless because the damage has already occurred. Property owners will be quick to misdiagnose this damage as winter injury. However, looking under magnification will reveal the fungal fruiting structures that have caused this disease.
If you suspect fungal disease issues on your trees, find a tree service that employs Certified Arborists that are skilled in diagnosing which kind of disease you may have. If it is Needlecast, there are frequently recommendations to treat this fungi with tree disease control sprays. If damage has already occurred, it is too late to address it. However, don’t necessarily give up on your tree. If there is still a good amount of live tissue on the tree, be sure to add fungicide spraying for these diseases. By targeting the fungi during the time frame when the new growth emerges, you can drastically reduce most Needlecasts from developing and protect the tender, new needles. This method of spraying trees for disease often means spraying multiple times in short intervals as the new growth is emerging. Be sure to also address the cultural recommendations for your trees. Prune when possible to allow for better air circulation and also irrigate in times of drought stress. Fertilizing trees will also help to provide needed nutrients to promote better growth in the future. It won’t reverse or eliminate the chance for disease damage, but it will help with the overall health of your tree. All of these recommendations are part of a Plant Health Care program that your arborist may recommend.
If you have trees that are in need of inspection, diagnosis, and treatment, we would love to talk to you further about how we may help you with our tree services.
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