Judith, your oak leafs are stunning! For years, I have wanted to add some of these to my garden. How would these do just alone as a single specimen out in the yard to train as a small to medium tree like plant?? I am loving this idea of the expanded bloom time of Snowflake! Got to find one!

Thank you for your comments Donna. I thought I'd answered your question, but I don't see the answer here so I must have done something wrong. I'll try again. The only hydrangea that can be used as a small to medium tree is the Hydrangea paniculata. The best variety to use, IMHO, is 'Limelight.' These are shrubs that have been trained (pruned) into nice trees and have become fairly easy to find in the garden centers. Below is a picture of a young H. paniculata 'Limelight.'

But Oakleaf hydrangea cannot be made into a tree. It is a loose, gangly shrub that, despite the crooked form, ends up looking beautiful. However, without the support of a wall or fence, it will only be a medium to large shrub. See bottom picture of Oakleaf 'Snowflake'.