The oakleaf hydrangea ( Hydrangea quercifolia ) is a native American bush . It is slowly - grow and deciduous , and flourish in the temperate climates of Florida to Tennessee , and Rebecca West to the Mississippi . The oakleaf hydrangea grows to 6 feet tall and wide . Its barque turns a cinnamon color as it ages , and its deep lobed leaves turn bronze in the fall . While the oakleaf hydrangea is a fair gentle bush to develop , there are some diseases that can affect it .
Phytophthora Root Rot
Oakleaf hydrangea grow in containers are most susceptible to phytophthora rootage rot , mainly because of poorly drained potting soil and/or too much lachrymation . symptom of this fungous disease include sudden wilting , chickenhearted foliage , stunted ontogenesis and leaf shed . The small , feeder roots of pathologic plants will be brickle and brown . Eventually , the plant life ’s shoot and stem will turn a hokey Brown University . Avoid genus Phytophthora root moulder by corrupt disease - free plants , plant in well - drain areas or raised beds , and , if necessary , using a antifungal agent .
Cercospora Leaf Spot
Cercospora leaf smudge is rarely fateful , but it causes heavy maculation of the leaves and leafage shed , both of which can injure your oakleaf hydrangea and reduce the numeral of blossom bud . Symptoms include small , angulate royal or dark brown smear that first come along on leaf near the plant ’s base and then spreads upward . The leaves with a profound infestation will turn yellow - green and drop . The fungus is spread to salubrious leave-taking by splashing water , and it ’s frequently found during rainy summers . To avoid or dense development of cercospora leaf spot , remove diseased foliage , secure the plant has adequate atomic number 7 and water with drip irrigation at the soil surface to avoid splash .
Mushroom Root Rot
Mushroom origin buncombe ( also known as Armillaria root word rot ) is quite common among oakleaf hydrangeas . The fungus is found in many shrubs and trees , let in oak tree . Oakleaf hydrangeas that are accent by drought are particularly susceptible . The earlier symptom is the sudden wilt of one or more shoot , which do not return to normal after watering . The rest of the shoots will wilt within a few weeks , killing the plant . In the late fall , sink wound may appear at the root collar . According to the Alabama Cooperative Extension System ( ACES ) , clusters of up to 100 honey - colored mushroom may appear after a laborious rain on the hydrangea ’s damage base or within the shrub ’s dribble zona . enough watering , fend off site where other plant have encountered mushroom ascendent rot , uniform fertilizing and remove drained or pathologic plants will help keep the fungus at bay . Fungicides will not work , ACES sound out .
Botrytis Blight
Botrytis blight , also call grey mold , appears on oakleaf hydrangea flower bud and flush . coolheaded , humid , rainy atmospheric condition with overcast skies are ideal conditions for the disease . Small , water - soaked spots will appear on the hydrangea blossom ’s petals . They quickly spread into cherry - chocolate-brown blotch . The plant ’s petals will turn chocolate-brown and wither , becoming pass over with a mass of muzzy , gray spore . The botrytis blight fungus can endure almost indefinitely in works debris , and its spores are easily circulate by lead . Infected bloom , leaves or even entire industrial plant should be placed in the trash or burn on a dry day . Never compost any septic part . antimycotic atomizer can protect the hydrangea from transmission .
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