As the garden winds down in the later part of summer, panicle hydrangeas (Hydrangea paniculata) take center stage offering up big blooms that put on a show from now into fall.
While we all love their more familiar mophead cousins (H. macrophylla), panicle hydrangeas have a few advantages. They bloom in full sun or morning sun (see below) which means more of us can enjoy them. And since they bloom on new growth each summer, there is no chance for flower buds to be damaged by winter cold, so you’re pretty much assured a blooming great show. Finally, butterflies and bees flip for the flowers which provide an important late season food source.
Panicle hydrangeas typically change color from white to varying shades of pink and, unlike mophead types, this is not as a result of soil chemistry. Instead color morphing is triggered by a change in air temperature. (Depth of color is more intense in colder northern zones than in warmer southern ones.)
If you haven’t planted a few panicle hydrangeas, either in garden beds or in containers, you’re missing out on one of the true treats in the late summer-to-early fall garden. Here are 7 that we recommend. (If you’d like a few ideas on how to design with them,check out this story.)
Sturdy stems support big, full flower heads that start out white and mature to a delectable pink. The long-lasting blooms are superb in fresh or dried arrangements. A grand slam for containers, foundation shrubs in smaller gardens, and mid-height borders. Up to 5′ tall, 4′ wide. Partial shade to full sun. Zone: 4 – 8
Easy Growing Tips for Success
Panicle hydrangeas need lots of sunlight to form those wonderful flower buds. Plant in full sun in cooler northern zones; in the south plant where they can get morning sun and afternoon shade.
Like all hydrangeas, panicle types love to be kept evenly moist. If you don’t have regular summer rains, water consistently to keep them happy, and to get the most intense color change from white to pink or red in the fall.
Panicle hydrangeas bloom on new wood (the current season’s growth) each year, so in late winter or early spring just as the new growth appears, prune for better branching and overall shape and to encourage new growth. Larger varieties can be kept compact by pruning; this can produce larger, if fewer, flowers.
Mid-Sized for Containers, Small Gardens, Landscapes
Very early bloomer opens white becoming dark rosy-pink in fall with great fall foliage color, too. Showy at the back of a border. Up to 8′ tall and wide. Filtered to full sun.
Drying and Arranging
Bunches of panicle hydrangeas can be cut right now when the flowers are a soft green for fresh, crisp summer arrangements, but they can also be harvested a bit later when they’ve begun to turn soft pink, typically in September or October depending on your zone and the weather.