Fertilising guide
How to fertilise Rough Hawk's-beard (Crepis biennis)— schedule & NPK
Also called Rough Hawk's-beard, Biennial Hawk's-beard.
More about rough hawk's-beard
About Rough Hawk's-beard
Crepis biennis · also called Rough Hawk's-beard, Biennial Hawk's-beard · flowering
Rough Hawk's-beard is a biennial native of European meadows, road verges, and rough grassland, naturalised across the UK. In its first year it forms a flat rosette of rough, hispid leaves; in its second year it sends up branched stems to 1.2 m bearing numerous yellow dandelion-like flower heads from May to July, after which it sets seed and dies. The key care fact for wildflower gardens is to allow some plants to set seed each year to maintain continuity, as no plant persists beyond two years. It is considered non-toxic to pets.
Growth habit: Biennial herb forming a flat, rough-leaved basal rosette in year one; erect, branching stems bearing many yellow capitula in year two, then dying after seed-set.
What fertiliser rough hawk's-beard actually wants — and why
Rough Hawk's-beard is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for rough hawk's-beard: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed rough hawk's-beard, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For rough hawk's-beard:
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. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when rough hawk's-beard is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for rough hawk's-beard
Half strength is the safe default for rough hawk's-beard — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water rough hawk's-beard first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the rough hawk's-beard watering schedule.
Signs you are over-feeding rough hawk's-beard
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for rough hawk's-beard:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding rough hawk's-beard
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full rough hawk's-beard care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of rough hawk's-beard with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for rough hawk's-beard
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising rough hawk's-beard — frequently asked questions
What fertiliser does rough hawk's-beard need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Rough Hawk's-beard is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed rough hawk's-beard?
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. 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. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for rough hawk's-beard?
Half strength is the safe default for rough hawk's-beard — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding rough hawk's-beard look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding rough hawk's-beard year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of rough hawk's-beard?
Flush the pot of rough hawk's-beard with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Rough Hawk's-beard care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water rough hawk's-beard — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise wisley gaultheria
- How to fertilise new zealand snowberry
- How to fertilise snowberry creeper
- All 10153 fertilising guides in the Growli library