Holly bushes are a common shrub used in landscaping and gardening. However, the holly bush is vulnerable to a number of diseases and parasites. While most of the diseases are caused by fungus, it is good to be know what can infect your holly bushes so you can get the proper treatment.
Tar spot is a fungal infection that occurs in the spring when the weather is cool and moist. It manifests as yellowish spots on the leaves. The leaves soon turn brown, then black, and eventually fall off. If you notice leaves of this colour, pull them off.
This fungus affects the stems. It causes sunken spots on the stems, which eventually die. To save your plant, you must cut out the infected stems and move them away from all your holly bushes.
Purple blotch occurs when the holly bush is injured or if a drought leaves it dry or without nutrients. Much like its namesake, the condition causes purple blotches all over the leaves.
Because the leaves of the holly are sharp, they can sometimes perforate one another, causing spine spot. The symptoms are similar to purple blotch except the leaves get grey spots that are ringed with purple.
Chlorosis appears when your holly bush is iron-deficient. The leaves will appear yellowish or pale green with deep green veins. You can treat this condition by balancing the pH level of your soil.