Encyclopedia Britannica - The definition of topiary along with the history and origin of the practice.
The Spruce - Find the best trees and shrubs for topiary.
Topiary Zoo - From garden topiary to tabletop topiary, this site explains it all.
Garden Destinations - Five of the world’s most fascinating topiary gardens open to the public.
Fresh Patio - Photos of fun topiary designs of animals which is a common theme for topiary.