ANTHRACNOSE - Many types of fungi cause anthracnose on various hosts.  The types usually involved with tree anthracnose in this area are Discula and Glomerella.The trees associated with the above fungi are ash, dogwood, oak, sycamore, and walnut. Dogwood anthracnose caused by the fungus (Discula destructiva) is the most serious disease of dogwoods in the landscape and our forests. Other species of anthracnose fungi attack the above hosts and can be equally  harmful.  The fungus involved causes dieback or even death of infected trees. The early symptoms begin in mid to late May as leaf spots with tan or purple borders.  In wet weather, these spots can rapidly enlarge and kill entire leaves. The infected leaves may remain hanging on the branches, especially in wet weather. The disease will then spread from the infected leaves into the twigs and branches and cause dieback of the limbs. If the dieback reaches the main trunk, the entire tree could be killed.  In order to distinguish anthracnose from other leaf spots, examine the underside of the leaves for numerous small tan to brown dots, about the size of a pin head (sometimes they're so small a hand lens or microscope is required to see them), scattered within the infected tissue. These dots are the source of spores that will be spread by rain, dew or insects to healthy leaves and neighboring trees. Under severe disease conditions, the flower bracts of dogwoods can become spotted. Prune out all dead or dying twigs and limbs during dry weather (refer to drought page).  In the fall, leaves should be raked up andremoved to help prevent a resurgence next spring.  Also, if possible, remove any dead leaves still attached to the branches.  Fertilizing affected trees is not recommended.  Fertilizing will cause new succulent growth that is highly susceptible to attracting the fungus. In areas with severe disease, consider replanting using resistant dogwood species such as kousa dogwood, (Cornus kousa), or hybrids between kousa and flowering dogwood such as  'Celestial', 'Milky Way' , 'Stardust' , 'Steeple' , 'Stellar Pink' and others. When disease pressure is severe, fungicides can be used on trees in landscapes in the spring at bud break, followed by additional sprays every 10-14 days until leaves are fully expanded. Trees should also be sprayed once in the fall after the leaves have changed color, but before leaf drop.