Tulip popular is one of those trees that has very few problems but having said that there still are a few plant diseases that attach this beautiful tree. The first one is powdery mildew. This plant disease is caused by Erysiphe or Phyllactinia fungus. The symptom of this plant disease is a white fungal growth on the top of the leaves. While this does give an unsightly appearance to the leaves, it never kills the tree.
I know at this point you are thinking that this problem is caused by moisture, this is somewhat true. Powdery mildew does not require standing water but it does need a lot of moisture. Also, it requires an outdoor temperature of 60 to 80 degrees Fahrenheit.
Powdery mildew, in this case, does not cause enough damage to really warrant any type of control.
Sooty mold is the other plant disease that tulip popular can suffer from but it does not attack the tree like you may think. What the sooty mold is actually attaching itself to is the honeydew that is produced by aphids. Before I can talk about control, I first must talk about aphids.
Aphids are little sucking insects that drink up plant juices. As they drink up, they produce as a byproduct or waste material called honeydew. As luck would have it, honeydew is one of the favorite foods of ants. In exchange for the honeydew, ants will protect the aphids from predators and will take care of their eggs.
When it comes to the tulip popular, the aphids begin to suck on the plant material. As they produce their waste, it drips down onto the lower branches of the tree. This is where you will find the sooty mold, which will grow on a shiny, sticky substance and turn it into a black growth.
The easiest way to control sooty mold is to control the aphids. One of the simplest ways of controlling the aphids is to eliminate the ants. This can be done by hitting them with a hard blast of water and/or introducing beneficial insects. One of the best insects to release into the environment is the ladybug. This bug can quickly get rid of the aphids. Having said that though, the leaves that have been covered with sooty mold will remain moldy but once the leaves have dropped, the problem should resolve itself.
As you can see, the tulip popular is a tree that has few enemies. In doing so, it is a great addition to any landscape space.