Answer: While you can control the symptoms of anthracnose with repeated sprays, you can never really cure the disease once your dogwood is infected. WSU suggests applying fungicides in the spring, starting at bud break and continuing every 10-14 days until the leaves are fully expanded. Further sprays may be necessary if the summer is unusually wet. Healthy trees are much more able to cope with disease than stressed trees. Keep trees stress free by applying 3-4 inches of mulch around the base (but keep the mulch off the trunk), watering during dry periods, and fertilizing moderately. Since shady moist conditions favor the development of this disease, avoid overhead irrigation and plant trees in sunny locations when possible. It is also advisable to avoid fertilizers with high nitrogen content as this promotes the rapid growth of succulent shoots that are extremely susceptible to disease. Avoid mechanical damage to any part of the tree especially by mowers or other equipment. Keep the inoculum levels low by raking and removing leaves in the fall, pruning diseased branches, and pulling adherent dead leaves from the tree. Prune any water sprouts that grow from the trunk. If possible, prune during dry, hot weather and disinfect the pruners blades in a solution of 70 percent rubbing alcohol between cuts. You might also consider replacing your infected dogwoods with more resistant cultivars so you won't have to enter such a long term care routine with your dogwoods.
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