Orange hawkweed.

At a glance

Care level

Easy

Plant type

Perennial herb

Light

Full sun

Indoor light

Direct sun

Water

Every 5 to 10 days

Mature size

12 to 18 inches

Growth rate

Fast

Hardiness

USDA 3 to 8

Bloom time

Early to late summer

Care

Plant this in a spot with plenty of sun to keep those colors bright. Watch for wilting if the soil dries out too much, and trim back spent flowers to encourage more blooms. It is a tough plant that handles poor soil quite well.

Watering

Water when the top of the soil feels dry; established plants handle dry spells well and dislike soggy soil.

Feeding

Apply a balanced liquid fertilizer during the active growing season.

Pruning

Deadhead spent flowers regularly to keep the plant tidy and promote new growth.

Repotting

Repot when the plant becomes root bound or starts to crowd its container.

Soil

Well draining, sandy or rocky soil

Soil pH

5.5 to 7.0

Temperature

-30 to 30°C

Humidity

40 to 70%

Safety

People

The plant contains sesquiterpene lactones which can cause skin irritation in sensitive individuals.

Children

The plant is not toxic but its hairy texture can be irritating to a child's skin if handled frequently.

Contact allergens

Handling the foliage may cause contact dermatitis due to the presence of fine hairs and sap.

Airborne allergens

The pollen can trigger mild allergic reactions in sensitive individuals during the peak bloom period.

Edibility

This plant is not considered edible and may cause digestive upset if consumed.

How to identify it

• Bright orange flower heads
• Hairy, lance shaped basal leaves
• Stems covered in black hairs
• Milky sap inside stems
• Spreads via stolons

Height

0.2 to 0.4m

Spread

0.3 to 0.6m

Leaves

green, deciduous

Flowers

orange, red, 1 to 2cm

Fruit

white, late summer

Problems to watch for

• RustCommon
• AphidsUncommon
• Powdery MildewUncommon
• Root RotUncommon

Growing it

Propagation

division, seed, stolons

When to plant

spring, autumn

Because this plant is so aggressive, it is best grown in containers or isolated areas to prevent it from choking out your other garden favorites.

Grows well with

• Sheep Fescue · It shares similar soil requirements and thrives in the same dry, sunny conditions.

Similar species

• Mouse Ear Hawkweed · It is a closely related species with similar growth habits but yellow flowers.

Science

Family

Asteraceae

Genus

Pilosella

Order

Asterales

Class

Magnoliopsida

Native range

Central and southern Europe.

Conservation

It is considered an invasive weed in many regions outside its native range and should be managed carefully.

It thrives in nutrient poor, acidic soils where it uses its stolons to rapidly colonize open spaces.

Value to wildlife

nectar source

Pollinators

bees, butterflies

Uses

ground cover, rock garden plant, meadow planting

Taxonomy resolved against GBIF.

Questions people ask

Is this plant invasive?

Yes, it is highly invasive in many parts of North America and can quickly take over lawns and pastures.

How do I stop it from spreading?

You must remove the entire root system and stolons, as any remaining pieces can sprout new plants.

Where the name comes from

The genus name Pilosella comes from the Latin word for hairy, referring to the plant's fuzzy leaves, while the species name aurantiaca refers to its orange flower color.

Good to know

• It is commonly known as orange hawkweed.
• The plant produces seeds without fertilization, a process called apomixis.
• It can outcompete native grasses in poor soils.
• The flowers close up during the night or on cloudy days.