Add Yahoo as a preferred source to see more of our stories on Google. Large oak tree in front of nice neighborhood Oak trees have been around for more than 50 million years, with individual trees ...

A close-up of an oak leaf with bumps, or galls, from the gall wasp, Photo courtesy Getty Images. Welcome to our tree column, “Ask your local arborist.” Each month, arborists from the Davey Tree Expert ...

Many coast live oak (Quercus agrifolia) trees are showing unusual browning in their canopies in the last month or two. If you look carefully, you may see small, crescent-shaped galls forming on the ...