Pee Gee HydrangeaHydrangea paniculata 'Grandiflora'
This is the most common H. paniculata form. It can be grown either as a large shrub or small tree, and it is known for its large panicles of white flowers. In fact, with some good pruning, this shrub can produce flower clusters measuring up to 12-18" in length!
To train as a single-stemmed tree: Select the straightest and strongest stem to use as the trunk. Stake the stem. Prune out additional stems, leaving 3–4 branches on the upper ¼ of the plant. Every spring, remove branches from the bottom ¾ of the plant and prune the top to a desired shape.