There is no denying the wow factor of the panicle hydrangea, especially when it’s in bloom. The flower trusses are in-your-face big, averaging 6 to 8 inches long, but they can be much bigger. Even better is that the robust blooms sit atop stout branches during the dog days of summer, when other shrubs have finished their show. Panicle hydrangea (Hydrangea paniculata
cvs., USDA Hardiness Zones 3–8) is a great old-fashioned shrub. I clearly remember having to duck under a huge canopy of blooms while delivering newspapers as a boy. I’ve seen a countless number of different panicle hydrangeas since my paper-route years—a testament to their reliability and popularity.
Panicle hydrangea is undergoing a renaissance of sorts, with a plethora of fresh cultivars making this vintage shrub relevant again. The influx of new cultivars in the 1990s, as well as the obvious similarity among some cultivars, fueled my interest in beginning a plant trial in 1999. Let’s be honest: Comparing the flowers can be like staring at a Magic Eye stereogram and waiting for the hidden image to appear. How distinct are the plants, really? Are the new cultivars improvements over the old ones or just more of the same? I knew that, by planting the cultivars side by side, their similarities and differences would become clear—and, boy, did they ever.