Tormentil

How to recognise it

Habit

Low perennial of 10–30 cm with thin, sprawling or ascending, branched stems; forms loose tufts.

Leaf

Stem leaves stalkless, with three leaflets and two large, cut stipules, so the leaf appears to have five. The basal leaves are stalked and often vanish before flowering.

Flower

Bright yellow, 7–11 mm across, with four petals (very occasionally five), single on long stalks, from May to September.

Fruit/Seed

Small dry nutlets in the persistent calyx.

Roots

A thick, knobbly, woody rhizome that turns red inside when cut.

Look-alikes

Creeping cinquefoil has five petals, stalked, hand-shaped leaves and rooting runners. Trailing tormentil often has flowers with four and five petals and stalked stem leaves. Tormentil always has stalkless stem leaves and nearly always four petals.

Flowering: May–September · Pruning: October

Why grow it?

• A long flowering season, from May to September, with nectar and pollen for small bees, hoverflies and flies.
• Foodplant for the caterpillars of the grizzled skipper, a small butterfly of thin grassland.
• The tormentil mining bee collects pollen almost only from cinquefoils, especially tormentil.
• A tough, low plant for poor, acid soil where few other flowers survive.
• Of historical interest: the rhizome was once used to tan leather and to dye red.

Tormentil: where does it grow best?

• In the wild: heathland, acid grassland, thin verges, clearings in oak and birch woodland, bogs and damp, poor pastures.
• Poor, acid soil: sand, peat or weathered loam; it disappears on chalky or fertilised soil.
• Sun to partial shade; tolerates both dry and damp spots.
• In the garden: in a heather garden, a thin lawn on sandy soil, at the foot of a birch or among heathers.

Goes well with

• Heather: Together in a heather garden on poor, acid sand.
• Cross-leaved heath: For the damp part of the heather garden.
• Heath bedstraw: A white-flowered mat between the tormentil, also on acid soil.
• Devil’s-bit scabious: Blue pompons in late summer on the same poor, damp soil.
• Harebell: Blue bells among the little yellow stars on dry, poor soil.

Tormentil: when and how to plant it?

1. Buy plants from a nursery for native wild plants, or seed of wild, native origin. Never dig up plants from the wild.
2. Sow in autumn (September–November) in a pot or tray of sandy, poor compost and leave it outside: the seed needs a cold spell.
3. Press the seed in lightly and barely cover it; keep it moist. Plant the young plants out in spring.
4. Plant pot-grown plants in spring or autumn, 20–30 cm apart, in groups of three to five.
5. Do not add compost or potting soil to the planting hole: on rich soil tormentil is quickly smothered by grasses.
6. Water after planting and keep the soil moist for the first few weeks.

Care

Watering

Not needed once established.

Feeding

Never. Poor soil keeps grasses and nettles in check.

Mowing

Mow a thin meadow or small heath once a year, in October, and remove the cuttings.

Competition

For the first few years, pull out tall grasses and coarse weeds around the young plants.

Self-seeding

Let the plant finish flowering; it sows itself on bare, acid patches.

Tip: Give tormentil the poorest, sunniest spot in your garden: the thinner the soil, the less competition and the longer it flowers.

Pruning and mowing

Pruning months: October.

When: Mow once a year, in October, along with the rest of the thin meadow or heath.

How:

• Cut at 5–10 cm and rake off the cuttings so the soil stays poor.
• Leave a patch uncut here and there until spring, as shelter for insects.
• Single tufts in a border need no cutting back: the old stems die off by themselves.

Caution: Do not mow in summer: you would lose the flowers and the caterpillars of the grizzled skipper.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow in autumn in a tray left outdoors; it germinates in spring after the winter cold.

Division

In March or October, split a tuft with a piece of rhizome and replant straight away.

Tormentil: how does it get through the winter?

Hardy to −30 °C.

• Most stems die back; the plant overwinters with its thick rhizome and sometimes a small rosette.
• Fully hardy, even on open, cold heathland.
• In March–April the rhizome sprouts again.

Diseases and pests

• Smothering: On soil that is too rich, grasses soon grow over it. Reduce fertility by mowing and removing cuttings; never feed.
• Drying out: Young plants can dry out in a dry spring; water them in the first year.
• Slugs: They sometimes eat young plants. Plant in autumn so they are strong when slugs become active in spring.
• Chalky soil: On chalky or limed soil it fades away. Choose an acid spot, for example among heathers.

Through the year

• March: New shoots from the rhizome. Still time to divide.
• April: Plant. Remove tall grasses around young plants.
• May: The first flowers.
• June: Full flower; look for small wild bees and the grizzled skipper.
• July: Flowering.
• August: Flowering. Seed ripening.
• September: Last flowers. Sow in a tray outdoors.
• October: Mow and remove the cuttings. Plant or divide.
• November: Still time to sow. Resting.
• December: Resting; the rhizome overwinters.

Did you know?

• The name tormentil comes from the Latin tormentum, ‘torment’: the rhizome was once used in folk medicine for stomach ache.
• The rhizome is rich in tannin and was once used to tan leather and to dye wool red.
• Tormentil is one of the few cinquefoils with four-petalled flowers; most others have five.