Slide show: 20 gorgeous peonies

What's new: Itoh, or intersectional, hybrids are crosses between herbaceous and tree peonies. They grow to 3½ feet tall; pump out flowers in shades of lavender, pink, copper, yellow, or cream; and bloom over a longer period than standard herbaceous types.

Their stems are pencil thick―much stronger than those of herbaceous kinds―so they’re good at holding up big cups of petals.

Where to grow: Peonies thrive in cooler climates (Sunset zones 1-11; A1-A3), where they get pronounced winter chill. But some (see below) will grow well in warmer climates. All are also worth a try in dappled shade in zones 14–20. There, give plants afternoon shade and ample water.

When to plant: Set out container-grown plants in late April in warmer climates, May or June in cold-winter areas. Expect more bloom from 3-year-old peonies in 5-gallon containers.

How to plant: 

From nursery containers, in spring or fall: Loosen the soil and mix in generous amounts of compost, then place the plant in the ground with the top of its rootball level with the soil, taking care not to disrupt tender feeder roots. Or transplant it into a large (18- to 24-inch diameter) container that is wider than deep.

From roots, in fall: Plant herbaceous peony roots with eyes 2 inches deep in cold climates, 1 inch deep in warmer regions. Itoh hybrids should be planted 3 inches deep in cold climates, 2 inches deep in warmer areas.

How to water, feed: Water regularly. Feed with low-nitrogen fertilizer (such as 5-10-10) as the first leaves unfurl in spring, then again after the last flower fades.

When to pick: To harvest blooms for bouquets, cut stems just as flower buds begin to open (leave at least three leaves to nourish the plant for the following year); they’ll last up to a week in vases. Most varieties produce one bloom per stem, although Itoh hybrids produce more blooms per stem as the plants age.

Post-bloom care: In autumn, cut herbaceous and Itoh hybrid peonies to the ground; new growth will emerge the following spring.

Pick up a peony

Choose:

For cool climates: Three new Itoh hybrids (crosses between tree peonies and herbaceous peonies): ‘Bartzella’ (very large bright yellow blooms), ‘Pink Double Dandy’ (pink, of course), or ‘Yellow Doodle Dandy’.

For cool or warm climates: Four herbaceous favorites: ‘Blaze’ (bright red single), ‘Festiva Maxima’ (white double with crimson flecks in the center), ‘Sarah Bernhardt’ (pink), or ‘Sea Shell’ (satiny pink single).

Shop: Buy plants (up to $100 at nurseries for Itoh hybrids, or $40 for standard herbaceous), starting in late April in warmer climates, May in cooler regions. You’ll get the most reliable bloom from 3-year-old plants in 5-gallon pots.

Tour and buy: Around 200 varieties of herbaceous and tree peonies start blooming in late March and continue into June at Chateau CharMarron Peony Gardens (5335 Sierra Rd., San Jose; 408/251-7048). Next month, view 300 varieties covering 10 acres at Adelman Peony Gardens (May 1–Jun 15; 5690 Brooklake Rd. N.E., Salem, OR; 503/393-6185).

More: