Bristly oxtongue.

At a glance

Care level

Easy

Plant type

Biennial herb

Light

Full sun

Indoor light

Direct sun

Water

Every 7 to 14 days

Mature size

3 feet

Growth rate

Medium

Hardiness

USDA 6 to 10

Bloom time

Late spring to early autumn

Care

This plant thrives in full sun and well drained soil. Watch for wilting during extreme heat, though it is generally drought tolerant once established. Keep an eye out for aphids that might cluster on the flower buds.

Watering

Water deeply when the top inch of soil feels dry to the touch.

Feeding

Apply a balanced liquid fertilizer sparingly during the active growing season.

Pruning

Remove spent flower stalks to encourage a tidy appearance and prevent unwanted self seeding.

Repotting

Repot only if the plant becomes root bound in its container.

Soil

Well drained, loamy or sandy soil

Soil pH

Neutral to slightly alkaline

Temperature

-10 to 35°C

Humidity

30 to 70%

Safety

People

There are no reports of significant toxicity to humans.

Children

The stiff, prickly hairs on the leaves and stems can scratch delicate skin, so handle with care.

Contact allergens

The stiff, hooked hairs can cause mechanical skin irritation upon contact.

Airborne allergens

The pollen may trigger mild allergic reactions in sensitive individuals.

Edibility

Young leaves are sometimes eaten as a potherb, but the bristly texture makes them unpalatable to most.

How to identify it

• Rough, bristly hairs on leaves
• Yellow flower heads with bracts
• Basal rosette of lance shaped leaves
• Milky sap inside stems

Height

0.3 to 0.9m

Spread

0.2 to 0.45m

Leaves

green, deciduous

Flowers

yellow, 2 to 3cm

Fruit

brown, Summer to autumn

Problems to watch for

• AphidsCommon
• Powdery MildewCommon
• Slugs and SnailsCommon
• CaterpillarsUncommon
• Leaf MinersUncommon
• RustUncommon

Growing it

Propagation

seed

When to plant

spring, autumn

Plant in open, sunny areas where it can naturalize without crowding out smaller, less aggressive species.

Grows well with

• Common Poppy · They share similar environmental needs in meadow settings.
• Cornflower · This plant provides a nice color contrast to the yellow flowers.

Similar species

• Hawkweed · They share similar yellow dandelion like flowers.
• Dandelion · The flowers and growth habit are superficially similar.

Science

Family

Asteraceae

Genus

Helminthotheca

Order

Asterales

Class

Magnoliopsida

Native range

Mediterranean region and parts of Europe.

Conservation

It is considered a widespread weed in many regions and is not of conservation concern.

It thrives in disturbed soils, roadsides, and waste ground where it can outcompete other species for light.

Value to wildlife

nectar source

Pollinators

bees, butterflies

Uses

wildflower meadows, pollinator gardens

Taxonomy resolved against GBIF.

Questions people ask

Is it a weed?

Yes, it is often considered an invasive weed in agricultural fields and disturbed areas.

How do I control it?

Hand pull the plants before they set seed to prevent spread.

Where the name comes from

The genus name Helminthotheca comes from Greek words meaning worm and case, referring to the worm like appearance of the seeds. Echioides means resembling Echium, another plant with bristly foliage.

Good to know

• The common name bristly oxtongue refers to the rough, tongue shaped leaves.
• It is an annual or biennial plant that spreads readily by wind dispersed seeds.
• The flowers close up during cloudy weather or at night.