BIG, BLOWSY HYDRANGEAS are a summertime classic. No doubt, at least in part, because their generous blooms, in cool tones of blue, rose and icy white, ask so little of us on hot days when we don’t feel like gardening.
A seaside-cottage garden favorite that thrives in our mild Pacific Northwest climate, hydrangeas lend themselves to naturalistic as well as more formal plantings. A hedge of Hydrangea arborescens ‘Annabelle’ smartly edged in clipped boxwood is as sophisticated as crisp white linen and an icy Pimm’s cocktail. While the sultry shades of late-season blue and rose mophead flowers (Hydrangea macrophylla or H. serrata) are more tie-dye and sangria. Which is to say, there’s a hydrangea for all of us.
I turned to Nita-Jo Rountree, a masterful gardener with a huge heart for hydrangeas, for a list of her preferred plants. “How many favorites would you like?” she replied.
It’s tricky asking a gardener to name favorites. “If I had to narrow it down, I guess ‘Miss Saori’, the award-winning plant of the year at the 2014 Chelsea Flower Show,” she said. “Then there’s ‘Zebra’ [from Xera Plants] and, of course, ‘Annabelle’.”
See what I mean?
Hydrangeas come in a variety of flower forms, from large ball-shaped blossoms to delicate, starry lacecap forms and graceful arching conical flowers. All of the blooms are remarkably long-lasting, ripening through a spectrum of rich colors as the season winds down and the weather cools. Hydrangea leaves are primarily green, although you’ll find a few with clean green and white variegation, and some varieties of H. serrata have dark stems and handsome wine-stained foliage.
Most hydrangeas prefer morning sun and afternoon shade. They can take full sun, but risk leaf burn when we have occasional hot days in spring before the new foliage has hardened off. Others, like oak leaf (H. quercifolia), panicle (H. paniculata) and smooth hydrangea (H. arborescens), like full sun. ‘Little Honey’ oakleaf hydrangea is an exception, with golden-green foliage that glows in the shade — this one is not sun-tolerant. Enrich planting beds with compost, and mulch well to create ideal well-drained yet moisture-retentive conditions. Provide regular water, although established shrubs are more drought-tolerant.
Nita-Jo’s pro tip on pruning: “Don’t!” Most hydrangeas bloom on wood that is at least a year old; a misplaced cut means no flowers! In her hydrangea lectures, she advises gardeners to simply remove faded flowers from macrophylla, serrata and quercifolia hydrangeas. To rejuvenate mature plants, remove any dead wood and prune the oldest stems entirely back to the ground to encourage new growth and future blooms.
Today’s market contains many “new and improved” hydrangeas that supposedly bloom on old and new wood — although Nita-Jo told me secondary blooms are light. Better to select newer compact varieties that will stay within their allotted garden space. With growth to just 4-by-4 feet, these mannerly shrubs are perfect for container growing as well. Stronger stems, another breeding improvement, don’t flop under the weight of the large flower heads and are a boon for flower arranging.