“What is causing these lumps (above) on my live oaks?” asks Birds & Blooms reader Katherine Gerritsen of Grand Cane, Louisiana. Horticultural expert Melinda Myers says, “Abnormal growths on a variety ...

Persisting in the winter months as ball-shaped shells on oak trees, galls, which are considered an eyesore by landscapers in the summer months, appear as a sort of curiosity in winter. What are these ...