Pine needle rust is a type of plant fungus that affects pine trees. The fungus causes the needles to turn yellow or brown and fall off the tree. Pine needle rust can also cause the bark to become discolored and cracked. If left untreated, pine needle rust can kill the tree.
To diagnose pine needle rust, look for yellow or brown needles on the ground beneath the pine tree. Also look for discolored bark and/or cracks in the bark. If you see these signs, call a Licensed Tree Expert for diagnosis and treatment.
Pine needle rust is common in areas with high humidity and rainfall. The fungus that causes pine needle rust is spread by wind, rain, and insects.
To prevent pine needle rust, choose a rust-resistant variety of pine tree for your landscape. If you live in an area where pine needle rust is common, avoid planting pines near other trees or shrubs that could be infected with the fungus. Also, keep the area around your pine trees clean and free of debris. Prune away any diseased branches as soon as you see them.
If you have pine needle rust in your landscape, remove and destroy all infected plant material. Do not compost it. Also, avoid watering the tree during the day to reduce the humidity around the tree. Water the tree at the base of the trunk, not from above. This will help keep the needles dry and less likely to be infected with the fungus.
If your pine tree is already infected with pine needle rust, remove all fallen needles from the ground beneath the tree. Destroy any infected tissue by burning it or placing it in a plastic bag and putting it in the trash.
Once diagnosed, pine needle rust can be treated with fungicides. Mike Virgil of Precision Tree & Landscape, or other qualified professionals, in addition to treating the trees, can also properly fertilize your trees to reinvigorate them as they fight the fungus.