Botanical illustration of Ranunculus
Botanical illustration © thegardening.co
Outdoor Moderate ⚠ Toxic to pets

Ranunculus

Ranunculus asiaticus · Persian buttercup

Grown from claw-like corms, the Persian buttercup produces layer upon layer of tissue-paper petals in jewel and sorbet shades from late spring. It is half-hardy and hates cold, wet winters, so timing and sharp drainage make all the difference.

Difficulty 3 / 5 — a bit tender

Toxic to cats, dogs & people if eaten

Ranunculus (like the buttercups it's related to) contains protoanemonin and is listed as toxic on the ASPCA database. Chewing causes mouth irritation, drooling and stomach upset, and the sap can blister skin. It loses its toxicity once dried. Keep pets from grazing the fresh plant.

🐈 Cats🐕 Dogs👤 People🧤 Harmful to handle

Care at a glance

Everything that matters, in six lines. The detail is further down.

Position

Full sun

A bright, sunny spot brings out the fullest, most colourful flowers. It sulks in deep shade.

Water

Moist, never waterlogged

Keep evenly moist in growth, but sharp drainage is vital — sitting wet, especially when cold, rots the corms fast.

Hardiness

Half-hardy · ~ -3 °C

Takes a light frost but hates cold, soggy winters. Grow under cover, protect with fleece, or lift and store.

Soil

Rich, free-draining

Fertile but open soil, or a gritty compost in pots. Heavy, wet ground is the quickest way to lose it.

Feeding

High-potash as buds form

A high-potash feed as the buds appear keeps the flowers coming over a long picking season.

Flowering

Late spring to early summer

Weeks of ruffled, many-petalled blooms, superb for cutting.

The almanac · Ranunculus through the year

What to do, and when

Spring

Plant soaked corms claws-down in early spring for early-summer flowers, or plant out autumn-started plants once hard frosts have passed.

Summer

Flowering season — pick or deadhead often to keep buds coming, and feed and water in dry spells.

Autumn

In mild areas start corms under cover for early flowers; lift, dry and store summer corms, always protecting them from wet.

Winter

Corms rest dry and frost-free; cloche or fleece any plants left in the ground and above all keep them out of the wet.

Soak the corms, claws down

Ranunculus corms look like tiny brown claws, and they wake up fastest if you soak them for a few hours in water before planting — they'll swell to two or three times their size.

Plant them with the claws pointing downwards, a few centimetres deep. Get them upside down and they struggle to emerge; that, and cold wet soil, is where most people lose them.

Quick tell: the pointy claws face down, the knobbly crown faces up — soak first, and never plant into cold, soggy ground.

Beating the winter wet

The plant's real enemy is not cold so much as damp: corms sitting in wet, chilly soil simply rot. Sharp drainage, raised beds or pots, and protection from winter rain all help.

Many UK growers treat ranunculus almost as an annual — starting corms under cover, planting out in spring, and lifting to dry off for storage once flowering ends.

Common problems

Corms rot and never sprout

Planted into cold, wet soil, or corms sat too wet. Improve drainage, warm the soil, and don't overwater early on.

No growth after planting

Corms not soaked, or planted claws-up. Soak before planting and set them with the claws pointing down.

Grey mould on buds and stems

Botrytis in cool, damp, crowded conditions. Improve airflow and remove any affected growth promptly.

Distorted shoots and sticky leaves

Aphids on soft new growth. Rub them off or blast with water, and encourage ladybirds and other predators.

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Everything a ranunculus needs

A pre-soak, sharp drainage, and shelter from the winter wet.

Essentials — get these right and it thrives
The plant
Ranunculus corms
Choose firm, plump claws — bigger corms give more flowers.
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Compost
Free-draining, gritty mix
Open compost is what keeps the corms from rotting in the cold.
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Pot
Pot with drainage
Pots let you protect the corms from winter rain and lift them easily.
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Worth it — genuinely useful, not obligatory
Plant food
High-potash feed
Keeps the flowers coming over a long cutting season.
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Protection
Horticultural fleece
Covers plants through cold snaps when they're grown outdoors.
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How we checked this

Care cross-checked against the RHS. Toxicity confirmed against the ASPCA database, which lists Ranunculus as toxic to cats, dogs and people — the fresh plant contains protoanemonin, causing mouth irritation, drooling and stomach upset, and the sap can blister skin. If our page and these sources ever disagree, believe them — and tell us.

Sources: RHS · ASPCA — toxic & non-toxic plants

Last reviewed · July 2026