Updated: Apr 18, 2020
In the early 1900’s, plant breeders thought that crossing tree peonies and garden peonies was impossible because the two species were too far apart for it to work. In 1948, however, Dr. Toichi Itoh, was successful in creating seven intersectional hybrids of peonies by crossing the two, and maintaining some of the best aspects of both. Unfortunately, Dr. Itoh passed away before he ever got to see his masterpieces come to life.
American horticulturist, Louis Smirnow, year later bought some of the original Itoh peonies from Dr. Itoh’s wife and continued with his breeding work. Once Itohs were brought to the United States, several breeders began working with and developing new varieties. It was not unusual to see Itoh Peonies sell for $500-$1,000 per plant because of the amount of time it took to create divisions. While prices have come down from there to $40-$100 per plant because of quicker production through tissue culture, Itohs are still slow to produce large numbers of plants and so they remain more expensive that garden peonies.
From the tree peony side of the cross, Itoh peonies have very sturdy stems that don’t require staking, even though they have the larger flowers of tree peonies. Itohs have long lasting flowers and dark, lush, green foliage that is deeply lobed and lasts nicely through the summer. They resemble the tree peony in that they have a domed, vigorous growth habit and Itohs can have as many as 50 blooms in a single season.
They grow 3’ tall and wide and they only get better with age. Itoh peonies also have the superior disease resistance that comes from the tree peony genetics. Like the traditional garden peonies, Itoh’s die back to the ground each winter and have superior cold hardiness. Itoh peonies tend to bloom later than traditional garden peonies, thus extending the peony bloom season. The original Itoh peonies were all yellow, but through decades of breeding work there are now lots of amazing color, that you just can’t get from traditional garden peonies.
Itoh peonies prefer to be grown in full sun or part shade. They are Zone 4 cold hardy (possible Zone 3, as some growers have reported that they work in Zone 3 in Canada). They are deer resistant, easy to grow, have a wonderful dome shape, and the flowers are almost dinner plate in size. Itoh peonies, along with herbaceous garden peonies are just starting to break dormancy at the nursery right now. They were fall planted last year and overwintered at Garden Gateway, so they can be planted right now. No need to worry about freezing because they are coming up at their natural time. We are currently offering the Itoh Peonies for online sales for curbside pickup. Click here to see our peony collection in the store.
Garden Gateway is a Cache Valley (Logan) Utah Nursery, Greenhouse and Garden Center. We are famous for our gorgeous hanging baskets and sooooo much more!