I always think of the Itoh (pronounced EE-toe) peony as the poster child for modern plant breeding. Virtually unknown to Canadian gardeners until they began to make their way into commerce about a decade ago, many horticulturists consider Itoh (or “intersectional”) cultivars to be the peonies of the future, poised to replace the floppy “common garden” or herbaceous peonies (Paeonia lactiflora cvs.) so prized by our forebears.
Plant profile: Itoh peonies
Itoh peonies almost defy description: The plants themselves look like common herbaceous peonies – until they flower! While the deciduous nature of their P. lactiflora seed parent has been passed on, from their pollen parent they have inherited the enormous (+20-centimetre-wide) flowers we associate with tree peonies in a colour range that has expanded to include yellow, orange and copper, often with flares and streaks in contrasting hues.
Itoh peonies produce more flowers per plant than herbaceous peonies – 50 blooms is not unusual – they flower for a longer period, and they don’t require staking. Also, they’re less susceptible to downy mildew than herbaceous peonies, as well as being almost immune to the botrytis blight that can affect tree peonies. Hardy to Zone 3, you can grow Itoh peonies wherever herbaceous varieties thrive.