Some discoloration. Have a professional positively identify your oak tree's fungus before you treat it. Season: The disease can survive winter in infected twigs and leaves that do not drop, with signs emerging following bud break. Treatment: Trees typically die within one year of infection. Symptoms: Irregular, brown spots from between leaf veins. When they are afflicted by disease, they lose all of their aesthetic appeal. Season and Risk Level: Damage appears in spring and early summer. Causes: Reduced water uptake by trees, usually caused by some form of damage to the root zone, including drought and construction damage. Oak Leaf Blister. Most oak species are susceptible, but the red and black oak group are especially so. Once this disease progresses, it can be lethal. It starts with fall coloring out of season—the leaves are wilting and browning, and within a few weeks, the tree is dead. Follow the manufacturer's instructions and spray the leaves at budswell and then twice more at two-week intervals. Extensive leaf drop occurs by mid-summer. Manzate 200, Dithane M-45). Symptoms: Circular, dark to reddish-brown spots on the leaves; can run together creating blotches. Symptoms: Edges of oldest leaves turn brown, beginning on the inner and lower portions of the tree. These growths appear in large groups and are followed by a white fan of fungal growth under the bark at the base. By inspecting leaves and trunks, and looking for dead branches, you can figure out what ails your oaks. Examine the tops of the leaves for black to brown spots with light centers to determine if the tree has spot... 3. Symptoms: Honey-colored mushrooms form annually at the base of the tree. Remove infected trees quickly and inject neighboring oaks with a fungicide to inhibit spread. Immediately remove infected leaf litter and pull off any afflicted leaves. Eventually, branches and twigs die altogether. Blister-like patches appear on the leaves. Several oak tree diseases are caused by fungi. Causes: Many different bacterias cause this as they enter the tree through wounded bark. Symptoms: Dead areas appear between leaf veins, mostly on lower branches. Season: Infection occurs at any time, and severe damage becomes noticeable in summer and early autumn. Butler began blogging, editing and writing in 2000. Our arborist will recommend a plan to suppress the tree fungus. Oak root fungus almost exclusively attacks oak trees that are under cultural stress. Treatment: There is no treatment, but removing damaged branches can help slow the progression of the illness. The leaves of afflicted trees will lose their color in a few weeks before turning brown or yellow and dropping. Treatment: In general, pruning dead twigs and branches during dormancy is the best treatment. You pull on your gloves, carefully place safety glasses atop your nose, and grab your tools. Symptoms: Large groups of yellow to pink, shelf-like fruiting structures turn white with age; the bark where these form becomes depressed and cracked. Season and Risk Level: Symptoms appear late summer to fall, typically following a summer drought. Signs of oak root fungus include slowed growth, callus formation over tree wounds, cankers that ooze sap, cracked bark and thinning of the tree's crown. Treatment: Remove all infected plant material to slow spread. The fungus infects the inner bark causing the outer bark to slough off. As is true with most things, proper care is the best defense against any illness or setback. This fungus can infiltrate the wood of the tree and steal vital nutrients that are necessary for the tree to thrive. Symptoms: This white-rot fungal disease leads to the death of branches and leaves at the tree’s crown. Oak wilt is an important disease in urban areas where a trees are highly valued. Symptoms of oak tree diseases include discolored or spotted foliage, dead or dying foliage or branches, thinning canopy, shelf mushrooms or wet patches on the trunk. Spraying may be indicated for small trees that have lost their foliage several years in a row. When not busy learning about homes and appliances she's sharing that knowledge. Symptoms: A white growth on the surface of the leaves, both top and bottom. Trees located near structures should be removed for safety purposes. Fungicide is often unnecessary. Oak root fungus almost exclusively attacks oak trees that are under cultural stress. Treatment: Avoid wounding the bark to prevent further stress. With some varieties reaching heights of 100-feet, oaks need to be handled carefully and skillfully.