Peonies: Plants that bloom for generations… ants not required

Somewhere in peonies’ past, gardeners noticed that ants seemed to swarm over peony buds just before they opened. That lead to the myth that ants somehow are necessary to make peonies bloom. In reality, the ants are there to gorge themselves on the sweet nectar that the buds emit. Ants or not, the buds would open anyway into those gorgeous, rose-like flowers that make the peony a long-time favorite. Gardeners have grown this cold-hardy plant for generations. It’s such a long-lived species that peony plantings can easily outlive the planter, blooming each spring for decades with little care.

Two main types

The most common peony is a perennial flower (Paeonia lactiflora) – one that’s winter-hardy in Zones 3-8 and that grows a dense, 2-foot bush of green leaves in spring. By May, stalks poke up that produce marble-sized buds at the tips, followed by two to three weeks of rose-like white, pink, red or pastel blooms. The leaves brown in fall frost and get cut back to the ground

A second and even bigger-blooming peony is the tree peony (Paeonia suffruticosa). This one is a woody shrub – hardy in Zones 4-9 – that grows 3 to 6 feet tall and produces the same flower colors, plus yellow. It drops its leaves in fall, but the woody stems are left intact or pruned after bloom as with any other spring-blooming shrub. Tree peonies bloom in mid-spring – a few weeks earlier than perennial peonies.

A third and noticeably more expensive type is an “intersectional” peony or “Itoh hybrid.” These are a cross between perennial and tree peonies, giving a durable perennial plant with the big, showy blooms of tree types.

3 peony tips

1. Perennial peonies bloom best in full sun (at least 6 hours of direct sun per day). Tree and intersectional types do fine in sun or half-day sun.
2. Peonies make excellent cut flowers. Snip them just as the buds are opening.
3. Contrary to some advice, you can move peonies. They might skip blooming for a year or two afterward, but perennial types can be dug, divided and relocated. The best timing: right after cutback in fall.

by George Weigel