How to grow Ranunculus

Ranunculus asiaticus · Persian buttercup

Ranunculus (Ranunculus asiaticus) — a tuberous buttercup from the eastern Mediterranean with layered, rose-like double flowers in a rainbow of colours on stems good for cutting. It loves cool weather, flowers in spring and goes dormant once summer heat arrives. All parts are mildly poisonous to people, cats, dogs and horses, and the sap can blister skin.

Checked against sources: October 3, 2026

Quick facts

Type	Flower
Family	Ranunculaceae
Light	Full sun
Soil pH	5.8–6.3
Frost	tolerates light frost
Soil for sowing	from 5 °C
Germination	21 days
Where it grows	Greenhouse, Open ground, At home

When to plant

It tolerates light frost: sow straight into the bed about three weeks before your last spring frost.

In an unheated greenhouse everything moves about three weeks earlier.

Frost dates · When to plant

Care

Greenhouse

Stage	Watering	Temperature	Feeding
Growth	every 7 days	5…18 °C	balanced (NPK), at the start of the stage
Flowering	every 7 days	5…18 °C	—

Open ground

Stage	Watering	Temperature	Feeding
Growth	every 7 days	5…18 °C	balanced (NPK), at the start of the stage
Flowering	every 7 days	5…18 °C	—

At home

Stage	Watering	Temperature	Feeding
Growth	every 3 days	5…18 °C	balanced (NPK), at the start of the stage
Flowering	every 3 days	5…18 °C	—

Growing notes

Light

Full sun, at least 6–8 hours a day.

Soil

Light, sandy, cool and moist soil with excellent drainage, pH about 5.8–6.3; heavy clay and wet ground rot the corms.

Care

Soak the dry, claw-like corms for 3–4 hours in room-temperature water — longer soaking makes them rot. To flower a few weeks sooner, pre-sprout them in a tray of moist mix at 4–10 °C for 10–14 days until white rootlets show. Plant claws down, 5–8 cm deep and 15–23 cm apart, several weeks before the last frost date; where winters are mild, plant in autumn and cover with frost cloth in cold snaps. Sprouted plants take light frost, but corms freeze and rot below −4 °C. Keep the soil moist but never soggy; growth is best at 5–18 °C, and above about 21 °C the plants stop flowering. First flowers come about 90 days after planting and keep coming for up to 6–7 weeks — cut spent stems down to the base. Then let the leaves yellow, lift the corms, dry them and store them cool and dry, or simply plant fresh ones next year. Protect them from rodents and wear gloves when handling the plants.

Sources

Figures checked against these sources.