Hound’s-tongue

How to recognise it

Growth habit

Biennial: in the first year a rosette of leaves, in the second an upright flowering stem of 30–90 cm, branched near the top. It dies after setting seed. The whole plant smells of mice, especially when crushed.

Leaf

Grey-green, softly and silkily hairy, lance-shaped, with a smooth edge. The rosette leaves are stalked and up to 30 cm long; the stem leaves are smaller and stalkless.

Flower

Dull wine-red to purplish-brown, funnel-shaped, about 1 cm across, with five lobes, in clusters that are coiled at first and later lengthen. Flowers from May to July.

Fruit/Seed

Four flat, oval nutlets of 5–7 mm, densely covered with short spines with tiny hooks. They cling to fur, feathers and clothing.

Roots

A thick, deep, dark taproot.

Confusion with

Common comfrey has rough hairs, winged stems and drooping, tubular flowers. Viper’s-bugloss has blue flowers and bristly stems. Neither has the mousy smell or the hooked nutlets of hound’s-tongue.

Flowering: May–July · Pruning: July–August

Why grow it?

• A native dune plant with an unusual flower colour: dull wine-red to purplish-brown, rarely seen in a garden.
• The flowers in May–July are visited by bumblebees and other bees, which take nectar from them.
• Rabbits leave it alone, so it holds its own in grazed dunes and remains a nectar source there.
• Its hooked nutlets travel in animal fur: a textbook example of seed dispersal.
• Of historical interest: it was once used as a medicinal herb, which explains the species name officinale.

Hound’s-tongue: where does it grow best?

• In the wild: coastal dunes, dry sandy or chalky grassland, woodland edges, clearings and disturbed ground, often where rabbits graze.
• In the garden: sun to light shade.
• Dry, free-draining, sandy or limy soil. On wet soil it does not last long.
• Suitable for a dune or seaside garden, a dry, rough corner or a nature garden with no grazing animals nearby and away from paths.

Goes well with

• Viper’s-bugloss: Blue flowers and an equally strong bee magnet on dry, sandy soil.
• Lady’s bedstraw: Yellow, honey-scented sprays in summer; also a plant of dry dune grassland.
• Wild marjoram: Flowers in July–September, when hound’s-tongue is over, and attracts many butterflies.
• Biting stonecrop: Yellow cushions at its feet, on the same dry sand.

Hound’s-tongue: when and how to plant it?

1. Only plant it if no horses, cattle, sheep or goats graze nearby and no hay is made on your land.
2. Buy seed or plants from a native plant nursery; never dig up plants from the wild.
3. Sow in autumn, in September–October, outdoors in pots or where it is to grow, 1 cm deep. The seed needs a cold spell and germinates in spring.
4. Plant out young plants in spring or autumn, 40 cm apart. Move them while young: because of the taproot, older plants transplant poorly.
5. Water well once after planting; after that, watering is not needed.
6. To see it flower every year, sow in two successive years, or let it self-seed.

Care

Water

Not needed: it is made for dry dune sand.

Feeding

Do not feed. On poor soil it stays compact and sturdy.

Letting it seed

Being biennial, it only persists if seed drops. Let a few plants self-seed, but not along paths where dogs walk.

Spreading

Pull up unwanted seedlings with gloves on while they are young rosettes, before the taproot goes too deep.

Livestock

Keep it out of pastures and hay meadows. Dig it out there before it sets seed and never feed the cuttings to animals.

Tip: Grow hound’s-tongue in a dry, rough corner away from paths and pastures, and cut most stems after flowering: you enjoy the unusual flowers without your dog coming home covered in burrs.

Pruning and mowing

Pruning months: July–August.

When: In July–August, after flowering, if you do not want seed.

How:

• Cut off spent stems before the hooked nutlets ripen and turn brown.
• If you want it to self-seed, leave one or two stems in a spot where nobody walks.
• Put stems with ripe nutlets in the general waste bin, not on the compost heap, and never near a pasture.
• Leave first-year rosettes alone: they will flower next year.

Caution: Wear gloves: the plant is poisonous and the hooked nutlets cling to clothing and gloves.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow ripe nutlets in September–October outdoors in a pot or where it is to grow. After the winter cold they germinate in spring; the plant flowers in its second year.

Self-seeding

In a suitable spot it self-seeds. Move seedlings while young, as a rosette of a few leaves.

Hound’s-tongue: how does it get through the winter?

Hardy to −25 °C.

• In its first year it overwinters as a grey-green rosette; in its second year the plant dies after setting seed.
• Fully hardy, to about −25 °C.
• The dead flowering stems with hooked nutlets stay standing into winter and cling to anything that brushes past.

Diseases and pests

• Burrs in fur: The nutlets cling to the coats of dogs, cats and sheep. Comb them out after a walk and cut off spent stems along paths in good time.
• Poisonous to livestock: Especially dangerous in hay and silage. Dig it out with gloves on in pastures and hay meadows, before it sets seed.
• Root rot: On wet, heavy soil the taproot rots in winter. Choose a dry, sandy spot.
• Powdery mildew: Sometimes a white powder on the leaves in late summer; harmless, no need to do anything.

Through the year

• March: Overwintered rosettes start growing again. Plant out young plants.
• April: The flowering stems of second-year plants shoot up.
• May: Flowering begins: bumblebees on the wine-red flowers.
• June: Full bloom.
• July: Last flowers. Cut off spent stems if you do not want seed.
• August: The hooked nutlets ripen. Cut stems along paths; collect seed with gloves on.
• September: Sow in pots outdoors or in place. New rosettes appear.
• October: Sow or move young rosettes.
• November: The rosettes overwinter.

Did you know?

• The name Cynoglossum comes from the Greek kuōn, dog, and glōssa, tongue: the soft, elongated leaves look like a dog’s tongue.
• The whole plant smells of mice, a smell you notice especially when you crush a leaf.
• The hooked nutlets are a textbook example of seed dispersal by animals: they travel in the fur of rabbits, foxes, sheep and dogs.