Hawkweed oxtongue

How to recognise it

Growth form

Biennial to short-lived perennial of 30–100 cm, with a taproot and an upright stem that is much branched towards the top.

Leaf

Lance-shaped, 5–20 cm, wavy to toothed and rough-hairy. The lower ones form a rosette; the stem leaves half clasp the stem with their base.

Hairs

Stem and leaves bear stiff hairs with a double hook at the tip: the plant feels rough and clings to clothes and fur.

Flower

Yellow heads of 2–3.5 cm made up only of ray florets, in a loose, branched cluster. The outer bracts are spreading, dark green and bristly. Flowers from July to October.

Fruit/Seed

Slightly curved, transversely wrinkled achenes of 3–5 mm with an off-white, feathery pappus.

Confusion with

Bristly oxtongue has leaves with whitish, blister-like warts and large, heart-shaped outer bracts. Hawkweeds have no feathery pappus. Autumn hawkbit and cat’s-ear have a leaf rosette with almost leafless stems; hawkweed oxtongue has leafy stems and hooked hairs.

Flowering: July–October · Pruning: June and October

Why grow it?

• Flowers late and for a long time, from July to October, when many other flowers are over: an important late-summer source of nectar and pollen.
• Honeybees, bumblebees, hoverflies and solitary bees visit it, including species that mainly collect pollen from yellow members of the daisy family.
• The fluffy seeds fly off on the wind, and seed-eating birds pick them from the heads in autumn.
• A tough, drought-tolerant species for sunny verges, dykes and rough wildflower meadows on chalky or loamy soil.
• A lovely discovery under a hand lens: the hairs end in a tiny two-pronged anchor.

Hawkweed oxtongue: where does it grow best?

• In the wild on verges, dykes and railway embankments, in quarries, on waste ground and in dry, rough grassland and chalk grassland.
• Full sun.
• Dry to moderately moist, chalky or loamy soil; also on rubble and gravel.
• In the garden: in a sunny, poor wildflower meadow, a dry bank along the drive or a rough edge on chalky soil.

Goes well with

• Chicory: Sky-blue flowers on the same verge, another late bloomer.
• Knapweed: Purple flowers for butterflies and bumblebees in the same rough grassland.
• Wild marjoram: Pink flowers full of bees on the same dry, chalky soil.
• Viper’s-bugloss: Blue flowers, a magnet for bumblebees, on dry, stony ground.
• Wild carrot: White umbels among the yellow heads, all summer long.

Hawkweed oxtongue: when and how to plant it?

1. Sow seed of wild origin in September–October or March–April, from a nursery or seed supplier specialising in native plants, or plant pot-grown plants from such a nursery.
2. Sow on bare, loosened soil or in gaps in the turf. Press the seed in and barely cover it.
3. Keep the soil moist until the seedlings appear; they come up after a few weeks.
4. Plant 30–40 cm apart, preferably in small groups, among other flowers of dry grassland.
5. Water only until it is established; after that its taproot gets it through dry summers too.
6. Never dig up plants from the wild.

Care

Water

Not needed; the taproot draws water from deep down.

Feeding

Not needed: on poor soil it stays sturdy and flowers freely.

Mowing

Mow once late, in October, or twice: in early June and in October. Remove the cuttings. Mowing in July–September cuts off the flowers.

Spreading

Self-seeds on bare ground, but stays limited in a dense sward. Dig out unwanted rosettes with their taproot.

Letting it seed

Leave some plants standing into autumn so that the seed can ripen.

Tip: Do not mow your verge or wildflower meadow in August: let hawkweed oxtongue flower on until October, and you will have a nectar source when almost everything else is over.

Pruning and mowing

Pruning months: June and October.

When: In October, after flowering; in a wildflower meadow possibly also in early June.

How:

• Mow short in October and remove the cuttings.
• Leave a strip or a few plants standing into winter or spring: the stems shelter insects.
• A cut in early June keeps the plant lower and more compact; it still flowers profusely in late summer.

Caution: Do not mow in July–September: you would cut off the flowers just when insects need them most.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow on bare ground in September–October or March–April. In a wildflower meadow it also self-seeds.

Hawkweed oxtongue: how does it get through the winter?

Hardy to −25 °C.

• Overwinters as a leaf rosette with a taproot; fully hardy.
• The withered stems with fluffy seed heads stay standing into winter.
• Leave some standing: small insects overwinter in and between the stems.

Diseases and pests

• Aphids: Sometimes many aphids on the stem tips. They attract ladybirds and hoverflies; no control is needed.
• Seedlings in borders: Seedlings sometimes appear on bare soil. Dig out the rosettes while young, with the taproot.
• Hooked hairs: The hairs cling to clothes and fur. This is harmless.
• Disappearing: In a sward that is too rich and dense, or if it is mown during flowering, it disappears. Make the soil poorer and mow late.

Through the year

• March: Sow. Clear old stems.
• April: The rosettes grow. Sowing is still possible.
• June: Optional cut in early June. The flowering stems grow.
• July: Flowering begins.
• August: Full flower, busy with bees and hoverflies. Do not mow.
• September: Flowering and the first seed fluff. Sow.
• October: Last flowers. Mow and remove the cuttings; leave some standing.
• November: Leave stems standing for insects.

Did you know?

• Picris comes from the Greek pikros, ‘bitter’, as does the Dutch name bitterkruid: the leaves taste bitter.
• Hieracioides means ‘resembling hawkweed’ (Hieracium), a genus of yellow daisies with which it is easily confused.
• Under a hand lens you can see that the hairs end in two little hooks, like a tiny anchor: this is how the plant clings to fur and clothes.