When Do Peonies Bloom in Washington?

Peony buds swelling on the stems in late spring mean the show is close. Where you live in the state and which type you grow decide exactly when your plants open.

When Do Peonies Bloom in Washington?

Peonies bloom in Washington in May and June, and the window runs from mid-May to late June. That spread comes from variety, since some open early in the window and others wait until the end.

Tree peonies keep their woody stems through winter and are never cut back, which sets them apart from the herbaceous kind. The calendar for them is not separate from the range above, so watch the buds on your own plant rather than a fixed date.

How to Tell When Your Peonies Are About to Bloom

Peonies announce themselves well before the petals open, and signs in the bed tell you how close they are.

• Red shoots pushing out of the soil in spring show the plant has woken from its winter rest and the season is underway.
• Shoots that turn green and open into leaves mean the stems are building the height that will carry the flowers.
• Round buds forming at the stem tips tell you bloom is coming, so this is the time to stake or add a support ring.
• Buds that swell and then feel soft when pressed gently are close to opening during mild weather.
• Buds showing a strip of color at the seam mean the petals are about to unfold; this is a useful stage for cutting flowers for a vase.
• Healthy leaves with no buds can point to a plant set too deep, recent planting, or insufficient winter chill.

Watch the soft buds closely, because warm spells can open them quickly once they reach that stage.

When to Cut Back Peonies in Washington

Cut herbaceous peonies back in fall after a hard frost has blackened the foliage. The frost is the signal, and it matters more than a date on the calendar because the plant is storing energy in its roots until the leaves are killed or turn brown.

Use clean pruners and cut the stems down close to the soil line, taking care not to damage the eyes at the crown. Remove the cut stems from the bed.

Tree peonies are the exception. Their woody stems remain through winter, so leave them standing and remove only wood that is clearly dead.

How Peony Bloom Time Shifts Across Washington

Peonies need a cold winter rest to flower well, and Washington gives them very different winters depending on which side of the Cascades you garden on.

• East of the Cascades: Peonies do particularly well here because the winters are cold enough to give them the chill they need for the best bloom. Cities such as Spokane, Yakima and Wenatchee sit in this drier, colder part of the state.
• Puget Sound lowlands: Winters here are mild and maritime, so peonies get less chill and may flower more weakly. Plants still grow, but the show can be thinner than in a colder yard.

A cold pocket or a higher-elevation yard will give your peonies more of the chill they want than a sheltered spot beside the water.

Where to Get Peony Advice in Washington

Washington State University Extension is the state’s source of research-based gardening help, and its county offices answer questions about local soil, climate and varieties.

• The extension website carries peony and perennial guidance, and it is worth reading before you plan new beds or divide old clumps.
• Your county extension office can advise on conditions where you live, so call or visit when peonies fail to bloom or you are choosing a site.

Common Questions

Are Peonies Hardy in Washington?

Yes. Washington spans USDA Plant Hardiness Zones 4a to 9a, so the right answer depends on your area. Peonies do best in the colder parts of that range, and mild coastal yards give them less winter chill.

Can You Plant Peonies in Spring in Washington?

Fall is the better time. Tubers planted from September to October have time to settle in before the ground freezes, which gives the roots a head start.

Will a Newly Planted Peony Bloom the First Spring?

It may not. A newly planted or transplanted peony may not bloom the first spring.