No, we do not recommend trimming hydrangeas to keep them small for a variety of reasons. Cutting your hydrangea back severely can cause weak stems and reduced blooms, especially if it is a variety that blooms on old wood! Instead, we recommend choosing dwarf varieties. There are many to choose from, including Little Lime, Bobo, Invincibelle Wee White, Invincibelle Garnetta, Invincibelle Mini Mauvette, Fire Light Tidbit, Tiny Tuff Stuff, Wee Bit Grumpy, and more.