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A bright pink ranunculus flower in full bloom

Oregon · Washington · Idaho

When to plant ranunculus

Plant in the garden: Portland and Seattle Mar 15 – Apr 19; Spokane Apr 15 – May 20; Boise Apr 1 – May 6; Bend May 12 – Jun 16.

Ranunculus, or Persian buttercup, is a cool-season flower from the Mediterranean and Middle East grown for layered, paper-thin petals, and it lasts well over a week in a vase. Colors run from white and blush to deep red, orange and bicolors. All parts are toxic if eaten, to people and pets.

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Puts ranunculus on your free plan, with dates for your town and a spot in your beds.

Difficulty
Tricky here
Sun
Full sun
Spacing
6 to 9 inches apart
Planting depth
2 inches deep, claws pointing down
Frost
Leaves handle light frost; cover below about 25°F
Flowers
Blooms about 90 days after planting

Layered, rose-like cut flowers from small claw-shaped corms. Soak the corms for a few hours before planting. Young plants handle light frost but not a hard freeze, so keep frost cloth handy after planting.

Ranunculu planting dates

TownsPlant in the garden
Portland, OR, Seattle and Tacoma, WAMar 15 – Apr 19
Spokane, WAApr 15 – May 20
Boise and Meridian, ID, Astoria, ORApr 1 – May 6
Bend and Redmond, ORMay 12 – Jun 16

Dates for six main cities. For any of the other 80 towns, type it in the box at the top of the page or browse all towns.

Ranunculu year at a glance

TaskJFMAMJJASOND
PlantMarApr
Cut flowersMayJun

Around Portland. Colder towns, especially east of the Cascades, run a few weeks later; the table above has your town's planting dates.

How to grow ranunculus

  1. Pick a sunny spot with soil that drains well, and mix in an inch or two of compost.
  2. Plant soaked ranunculus corms on your city's dates, 6 to 9 inches apart. 2 inches deep, claws pointing down.
  3. Soak corms in room-temperature water for three to four hours first. After planting, water once and then only when the top inch is dry until leaves appear.
  4. Harvest: Cut when the buds are colored and soft like a marshmallow but not yet open. They last a week or more in the vase.

Growing ranunculus in your part of the Northwest

The same plant behaves differently on the wet west side, the foggy coast and the dry, colder east side.

West-side valleys

Willamette Valley, Puget Sound, southern Oregon

Ranunculus corms rot in cold, wet soil, so plant in late winter under cover or in well-drained beds. Protect from slugs.

Coast

Oregon and Washington coast

Mild winters suit ranunculus planted in fall with some protection.

East of the Cascades

Columbia Basin, Yakima, Boise, Spokane, north Idaho

Plant in early spring; heat ends bloom by early summer.

High desert and mountain towns

Central Oregon, high eastern Oregon valleys, McCall, Salmon

Plant in spring after hard freezes pass. Cool nights help ranunculus bloom longer.

More ranunculu varieties

More widely sold picks that do well somewhere in the Northwest. The tag says which part of the Northwest suits each one best.

Tecolote mix

Giant-flowered corms · About 90 days

The widely sold Californian strain with big, many-petaled flowers in mixed colors.

Both sides

Amandine series

Florist-grade, early · About 90 days

Strong stems and early flowers in clear colors. Popular with flower farmers who grow under cover.

West side

La Belle series

Italian florist type · About 90 days

Large, ruffled flowers on long stems. Often planted in fall under a hoop house for spring cutting.

West side

How much to grow

How many to plant

For cutting, 25 to 50 corms give a steady supply for a month or more.

In the vase

Cut ranunculus last a week or more in the vase.

Key numbers

Top care tip: Water once after planting, then hold off until leaves appear, since soggy corms rot.

Growing notes

What makes the difference in Northwest gardens, in plain language.

Planting the corms

Ranunculus grow from small, dry, claw-shaped corms. Soak them in room-temperature water for three to four hours until they plump, then plant 2 inches deep with the claws pointing down.

Many growers pre-sprout soaked corms in a tray of damp potting mix in a cool spot for 10 to 14 days before planting. That gives a head start and lets you skip any corms that rot.

Timing and frost

Young plants handle light frost but are damaged by hard freezes below about 25°F. In most of the Northwest they go in during early spring, with frost cloth on hand for cold nights. They bloom in late spring and stop when summer heat arrives.

Experienced west-side growers also plant in fall under a hoop house or cold frame for earlier, bigger plants. Outdoors without cover, fall plantings often rot in wet, cold winters.

Drainage and harvest

The corms rot in cold, soggy soil, so plant in a raised bed or loose soil that drains well, and don't water again until leaves appear.

Cut stems when the buds are colored and feel soft like a marshmallow. They open in the vase and last a week or more. Most gardeners replant fresh corms each year.

Good neighbors

Good neighbors

  • Anemones. Same planting time and raised-bed needs.

Pests and problems

What most often goes wrong with ranunculus in Northwest gardens, how to spot it and what to do.

Corm rot

Signs: Corms turn mushy and never sprout.

What to do: Raised beds with good drainage.

Frost damage

Signs: Blackened leaves after hard frosts.

What to do: Cover with frost cloth on cold nights.

Aphids

Signs: Clusters on buds.

What to do: Hose them off.

Common questions about growing ranunculus

When should I plant ranunculus in Oregon, Washington and Idaho?

Plant in the garden: Mar 15 – Apr 19 in Portland and Seattle, Apr 15 – May 20 in Spokane, Apr 1 – May 6 in Boise and May 12 – Jun 16 in Bend. Pick your town at the top of the page for your own dates.

Why did my ranunculus corms rot?

Too much water before the leaves appeared, or cold, poorly drained soil. Water once after planting, then wait, and use raised beds.

Do ranunculus come back every year?

Sometimes in mild, well-drained gardens, but they rarely bloom as well. Most growers plant fresh corms each spring.

When do ranunculus bloom?

About 90 days after planting. Spring-planted corms bloom in late spring and early summer.

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