Next in our series we explore two more hydrangea species. Smooth Hydrangeas (Hydrangea arborescens) and Mountain Hydrangeas (Hydrangea macrophylla ssp. serrata).

Smooth Hydrangeas

Smooth Hydrangeas are beautiful shrubs with huge white blooms.  Native to the United States, these large, white flowers emerge a light green and mature to creamy white. Some of the new varieties (such as invincibelle spirit) produce pink blooms.

  • These flowers are NOT pH dependent, which means you can’t change their color.
  • The leaves are typically heart shaped and dark green.
  • Most prefer to have some afternoon shade.
  • These hydrangeas bloom on new wood, so benefit from a late winter cut back close to the ground.


One of my favorite varieties is Annabelle.  This beauty has massive blooms up to a foot across that emerge in June and bloom through September. These blooms are so massive that the stems may not always be up to the task of supporting them, so Annabelle is a great shrub to plant en mass. Alternatively a wire cage or carefully concealed stakes will keep the stems upright. These beautiful shrubs get to be 3-5 feet tall and 4-6 feet wide. They like partial sun.


If Annabelle is too much work, look no further than Incrediball. It has huge white blooms, even larger than Annabelle.’ Even better is that this shrub can hold its own. Sturdy stems hold flowers upright without the need for additional support. Flowering on new wood, this shrub gets pruned back in the late winter, but only to 1/3 it’s size. This shrub is slightly taller than Annabelle getting to be about 4-5 feet tall and wide. This variety prefers sun, and like all the hydrangeas, it prefers moist, well-drained soil.

Invincibelle Spirit II

If you prefer pretty in pink, look no further than the Invincibelle Spirit II. Deep green foliage and sturdy stems that won’t flop. Large pink flowers that are not pH dependent, this beautiful shrub blooms from mid-summer all the way to autumn. The pink flowers fade to an attractive green. And $1 from each shrub sold goes to the Breast Cancer Research Foundation. Prune just above ground level in late winter and plant in full sun.

Mountain Hydrangeas

Some botanists categorize them as a subspecies of the more commonly known Bigleaf (Hydrangea macrophylla) hydrangea, while others consider them their own species. Either way, they are a beautiful hydrangea that is unfortunately often overlooked.

They have slightly smaller leaves than the Bigleaf hydrangea – the serrated edge is more pronounced, and they have a matte finish. Personally, I love the Mountain Hydrangeas. Interestingly enough, the mophead version with the round flowers is rarely seen on the Mountain Hydrangea. They sport the lacecap flowers instead, and they bloom prolifically. While the flowers are not as large as the Bigleaf lacecaps, the flowers are more abundant.

Blue Billow

Hydrangea serrata Blue Billow is a gorgeous Mountain Hydrangea. Delicate clusters of light blue (of pink depending on your pH) flowers that last for weeks and turn a stunning crimson as they age. Fall foliage is an attractive shade of burgundy. Blooms on old wood so little to no pruning is required. 3-4′ tall and 5′-6′ wide.

Click Here to Read Part 1 – Bigleaf

Next Up Part 3 – Panicle, Oakleaf and Climbing