Q: What are these enormous white-flowered hydrangea shrubs I see around town? They must be ten feet tall!

A: Since it is early May, I’ll bet you are seeing Chinese snowball viburnum, not one of the white-flowered hydrangeas. It’s an easy mistake to make because the flowers on the two shrubs look almost identical. To keep the confusion level high, there are actually four kinds of “snowball” viburnums! I have a key to distinguish them at bit.ly/GAsnowball.