Hydrangea: Choose the right type
For a long-lasting display of huge, showy blooms, few plant families can outperform variegated hydrangeas. Every year we see new varieties of hydrangea emerging, making this plant even more of a problem solver and landscape staple. To choose the right hydrangea, you must first answer two questions: How sunny is my location, and how much room do I have? The answers will lead you to the appropriate hydrangea family, so you can choose from the many gorgeous flowers available in that particular family.
To understand the enormous diversity, let’s group the most popular hydrangeas into six families: large-leaf (macrophylla), serrated-leaf (serrata), smooth-leaf (arborescens), varieties with cone-shaped flowers (paniculata), and acorns. -Leaf (quercifolia), and climbing hydrangea (petiolaris).
The largest and most famous group is the macrophylla, or large leaves. Large-leaf hydrangeas do best in partial or filtered sun, and without protection from the hot afternoon sun they will wilt and get sunburned. Most large-leaf hydrangeas have large, round flower clusters, or “mopheads.” Some, like ‘Twist ‘n Shout’, are ‘lacecaps’, large flowers with petals around the edges and delicate pearl-shaped petals in the centre, looking like old lace doilies.
The introduction of Bailey Nurseries’ Endless Summer series revolutionized hydrangeas by offering plants that thrive on new growth each year, ensuring continuous flowering. “Endless Summer”, “Blushing Bride”, “Twist n’ Shout” and “Bloomstruck” soon followed. Today, all new large-leaved species thrive on new wood, so you can count on blooms every year even if the plants are cut or the tips freeze.
Serrata (toothed leaf) Hydrangea is similar to the macrophylla except that it has smaller leaves and flowers and tends to be more compact. Most have lacecap-type flowers.
Hydrangeas (cone-flowering) have cone-shaped flower heads that continue to expand, with new flowers at the tip of the cluster. This prolongs their flowering period, and the flower heads change color as the season goes on. This group of hydrangeas is less attractive to Japanese beetles than most shrubs. Our favorite is ‘Limelight’, with huge, lime-green flower heads that turn pink and burgundy in fall. ‘Pinky Winky’ is a new introduction that has particularly huge flower heads. ‘Quick Fire’ is the oldest hydrangea that blooms every year. Most cone-flowered hydrangeas grow very large, need a lot of space, and can grow well in full sun.
Soft-leaved hydrangeas (treewood) are classic, old-fashioned “snowball” herbaceous shrubs with heavy flower mops. This family includes “Incrediball”, “Annabelle”, and “Invincible Spirit”. Most soft-leaved hydrangeas will thrive in full sun. ‘Annabelle’ is also known for being shade tolerant.
Oak-leaf hydrangeas have eye-catching, intense purplish-red foliage and exfoliating bark similar to river birch bark. These versatile plants do well in shade, so they make a great informal hedge or foundation planting where sunlight is scarce. The new “PeeWee” range fits into small spaces. Oak leaf hydrangeas are a solution to problems in shady areas and produce masses of vigorous blooms that can be dried for flower arrangements.
Climbing hydrangea (Petularis) looks stunning when climbing a stone wall, trellis or fence. It’s a problem solver for a tight family.
We often receive questions about managing hydrangea flower color with different soil amendments. In particular, blue varieties need acidic soil otherwise they will bloom pink. We recommend using plenty of peat moss mixed into the potting soil, since all hydrangeas prefer well-drained, acidic soil. We use “Holly Tone” fertilizer when we plant hydrangeas and continue to fertilize every year. Pine bark mulch is more acidic than hardwood, and helps maintain soil acidity over time. Adding garden sulfur, soil acidifier Espoma or Miracid will help maintain the blue color.
All hydrangeas benefit from pruning during the winter or early spring. Everywhere it is cut, it will branch and produce more stems, and therefore more flowers. Regularly clipping the first bud over last year’s cutting makes the plant stronger and gives it a great shape, while also doubling the number of flowers.
Steve Boehme is a landscape designer/installer who specializes in “renovating” landscapes. Let’s Grow is published weekly. Column archives are located on the “Garden Advice” page at www.goodseedfarm.com. More information is available at www.goodseedfarm.com or call GoodSeed Farm Landscapes at (937) 587-7021.