Know Your Hydrangeas
The following is a regular column that addresses basic issues facing the ever-inquisitive back- and front-yard toiler, proffered by Brian Cruey, who as General Manager of Naumkeag for the Trustees of Reservations, knows about beautiful gardens.
If one had to pick a true superstar of the late summer garden in our area, I think most would agree that hydrangea would take the honors. Big, showy, prolific blooms punctuate flower gardens across the region this time of year. It’s a show that extends well into fall as blooms often turn color from shades of white to pink and red, eventually drying on the branch, creating a point of interest that can last straight through the winter.
However, all hydrangea are not created equal. Though there are tons of cultivars, there are really four main types of hydrangea that are most common. That includes Hydrangea macrophylla (mopheads and lacecaps), Hydrangea aborescens (of the Annabelle family), Hydrangea paniculata and Hydrangea quercifolia (oakleaf hydrangea.)
These are usually the most colorful of the bunch with blooms that start out pink, blue, violet and white, which makes them unique to other hydrangeas because the others generally bloom white and turn colors as the season progresses. Also characteristic to this variety: the blooms grow on the previous year’s growth, so be mindful of when and how you prune. Hydrangea macrophylla can be divided into two groups: mophead and lacecaps. Mopheads are the larger, globular blooms that can range in size from an orange to a cantaloupe. Lacecaps are more subtle with sterile florets circling the tight, smaller fertile flowers in the center that bees go crazy over.
I’ll be honest – I haven’t had a lot of luck with Hydrangea macrophylla, which includes the very popular cultivar “Endless Summer.” Our cold winters and fluctuating springs often destroy the buds that have formed from the previous year. The plants of this variety that I have tried to grow in my garden get lots of foliage but rarely do they bloom.
This species is often referred to as Anabelle hydrangea due to the popularity of that cultivar, though more have been introduced over the years. This woody shrub can be pruned back in the spring as buds form on new growth. This hydrangea is often referred to as “smooth hydrangea,” “wild hydrangea” or “seven bark.” The globe-shaped blooms can be anywhere from two inches to 10 inches in diameter. The plant itself will usually stay between two and four feet tall.
This hydrangea gets its name from the panicle, cone-shape of its blooms and it is the only type of hydrangea that can be pruned into a tree form. Paniculata can tolerate hard pruning and will grow to be quite large, up to 10 feet. The blooms of paniculata often turn from white to pink to red as the season progresses and includes the popular varieties “PeeGee” and “Limelight.”
The Oakleaf hydrangea does well with little attention and can grow in more harsh, dry conditions than other species. It gets its name from the “oak leaf” shape of its foliage which turns beautiful shades of dark red and purple in the fall, making it an excellent choice for late-season color. Exfoliating bark also makes the woody stems of this plant a beautiful sight in the winter months. Like paniculata, the blooms of quercifolia are cone-shaped and white, though often slightly less prolific. Blooms for Hydrangea quercifolia grow on old growth so pruning should be restricted to winter damaged branches.