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Plant care

Rough Hawk's-beard (Biennial Hawk's-beard) care

Crepis biennis

Also called Rough Hawk's-beard, Biennial Hawk's-beard.

RHS H7USDA 5-9Pet-safeIndoor Rosette 20–40 cm across in year one

Watering rhythm

Direct sun (at least 4-6 hours)

Low — drought-tolerant, especially in the rosette year

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Light

Direct sun (at least 4-6 hours)

Soil

Well-drained to moderately moist, neutral to alkaline loam or clay

Humidity

Low to moderate (35–60 % RH)

Temp

-20 to 30 °C

Pet safety

Pet-safe

Mature size

Rosette 20–40 cm across in year one

Care at a glance

Light

Rough Hawk's-beard needs sun on the leaves, not just bright ambient room light. Requires full sun for vigorous growth and free flowering; shaded plants produce etiolated, weak stems that tend to flop and produce fewer flower heads. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water rough hawk's-beard low — drought-tolerant, especially in the rosette year. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Established rosettes tolerate extended dry spells; water lightly in the first weeks after sowing to aid germination and root establishment, then rely on natural rainfall.

Soil and pot

Rough Hawk's-beard grows best in well-drained to moderately moist, neutral to alkaline loam or clay. Naturally colonises road verges, field margins, and disturbed calcareous soils; performs well on moderately fertile grassland soils. Very rich soils encourage excessive leafy growth and weaker stems. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Rough Hawk's-beard sits happiest at around Low to moderate (35–60 % RH) humidity and -20 to 30 °C (-4 to 86 °F). Fully adapted to temperate British conditions; no humidity management is required. Prolonged damp around the rosette crown in winter can cause basal rot. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed rough hawk's-beard sparingly. No fertilising needed in wildflower settings; a single light application of a balanced granular feed in spring of the second year can increase stem and flower number in ornamental borders. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on rough hawk's-beard in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Powdery mildew on second-year stems — White powdery fungal coating is common on flowering stems in warm, dry summers; ensure adequate plant spacing for airflow and remove heavily infected material after seed-set.
  • Failure to persist — biennial lifecycle misunderstood — Plants die after flowering in year two; allow seed heads to ripen and disperse naturally, or collect seed and scatter in autumn to ensure a new cohort of rosettes for the following year.

Propagation

Sow seed in situ in late summer to early autumn (mimics natural timing); alternatively sow in modular trays in late summer and transplant rosettes to final position before winter. Surface-sow and do not cover deeply as seeds need light to germinate. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Rough Hawk's-beard is pet-safe. Crepis biennis is not listed as toxic by the ASPCA. Members of the Crepis genus are not documented as toxic to cats or dogs; the plant is considered non-toxic, though consumption of large amounts of any plant material may cause mild gastrointestinal upset. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Rough Hawk's-beard care — frequently asked questions

What is the common name for Crepis biennis?

Crepis biennis is most commonly called Rough Hawk's-beard, but it is also known as Rough Hawk's-beard, Biennial Hawk's-beard. The names refer to the same species, so care instructions for Rough Hawk's-beard apply identically to anything sold as Biennial Hawk's-beard.

How much light does rough hawk's-beard need?

Rough Hawk's-beard grows best in direct sun (at least 4-6 hours). Requires full sun for vigorous growth and free flowering; shaded plants produce etiolated, weak stems that tend to flop and produce fewer flower heads.

How often should I water rough hawk's-beard?

Water rough hawk's-beard low — drought-tolerant, especially in the rosette year. Established rosettes tolerate extended dry spells; water lightly in the first weeks after sowing to aid germination and root establishment, then rely on natural rainfall. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is rough hawk's-beard toxic to cats and dogs?

Rough Hawk's-beard is pet-safe. Crepis biennis is not listed as toxic by the ASPCA. Members of the Crepis genus are not documented as toxic to cats or dogs; the plant is considered non-toxic, though consumption of large amounts of any plant material may cause mild gastrointestinal upset.

What USDA hardiness zone does rough hawk's-beard grow in?

Rough Hawk's-beard is rated for USDA zone 5-9 and RHS hardiness H7. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Rough Hawk's-beard deep-dive guides

Every aspect of rough hawk's-beard care, each with its own calibrated guide:

Featured in these plant shortlists

Rough Hawk's-beard qualifies for 10 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Rough Hawk's-beard is also commonly called Rough Hawk's-beard or Biennial Hawk's-beard.