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Tulip Tree Disease

The tulip tree is also known as the yellow-poplar, tulip-poplar, white-poplar and whitewood, and is a member of the magnolia family. Tulip trees require a long time commitment. They can live to be about 300 years old. The tree grows in the eastern United States, from the southern part of New England, west through Michigan and southern Ontario in Canada, then south to Louisiana then back east to the north central part of Florida.


Tulip trees are susceptible to fungal diseases, some of them fatal in most cases. Armillaria root rot is also known as oak root fungus or shoestring disease. Verticillium wilt is a fungal disease that attacks the vascular system of the tree. Powdery mildew is a fungal disease that is common with many different plants.


The first symptoms of Armillaria root rot appear as leaves that are smaller than usual, discolored and drooping. Mushrooms might be seen growing from the base of the tree. Verticillium wilt appears as leaves that turn to a faded green, yellow or brown. Peel back the bark on the infected areas and there will be dark stains that run along the grain of the wood. Powdery mildew appears as a white, powdery growth of fungal spores on the leaves, flowers, fruits and shoots and it can be on both or either old and new growth.


Armillaria root rot will strike when the soil is too moist. The infection enters when the roots come in contact with the roots of other infected plants. Verticillium wilt occurs when the plant does not get proper irrigation and fertilization. Powdery mildew thrives in shady areas when the temperatures are on the moderate side.


For Armillaria root rot, make sure there are no roots from old trees in the site and let the air dry out the soil before planting. For Verticillium wilt, inspect the trees on a regular basis and remove any that are infected. Powdery mildew can be controlled planting in sunny areas and not over fertilizing. Watering can help by washing the spores off the tree and landing in water will kill them.


Armillaria root rot kills a layer of cells in the stems that is responsible for the growth of new tissue. Armillaria root rot can be fatal. Verticillium wilt can be fatal. The shoot and branches will wilt and die off, usually starting on only one side of the tree. If the tree does survive, it might still experience branch dieback. These branches need to be pruned off. Powdery mildew will cause the infected leaves to drop off early in the season.

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