Fertilising guide
How to fertilise Wood Avens (Geum urbanum)— schedule & NPK
Also called Wood Avens, Herb Bennet, Colewort, Old Man's Whiskers.
More about wood avens
About Wood Avens
Geum urbanum · also called Wood Avens, Herb Bennet · flowering
Wood avens is a semi-evergreen perennial native throughout the UK, found in shaded woodland, hedgerow bases, and damp scrub on a wide range of soils from acidic to calcareous. Small, bright yellow five-petalled flowers from May to August are followed by distinctive bur-like seed heads that cling to fur and clothing, aiding dispersal. It is one of the easiest shade-tolerant perennials for a wildlife garden, requiring no feeding and tolerating neglect, but it self-seeds freely and can become weedy. Wood avens is considered non-toxic to cats and dogs; the ASPCA lists avens as safe, and it has a long history of culinary use of the clove-scented roots.
Growth habit: Semi-evergreen perennial with a low basal rosette and upright flower stems, spreading freely by hooked bur seeds catching on passing animals.
What fertiliser wood avens actually wants — and why
Wood Avens 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 wood avens: 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 wood avens, 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 wood avens:
No feeding required; an annual top-dressing of leaf mould or garden compost in autumn is sufficient to maintain good flowering in lean soils. 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 wood avens 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 wood avens
Half strength is the safe default for wood avens — 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 wood avens first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the wood avens watering schedule.
Signs you are over-feeding wood avens
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for wood avens:
- 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 wood avens
- 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 wood avens care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of wood avens 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 wood avens
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 wood avens — frequently asked questions
What fertiliser does wood avens 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. Wood Avens 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 wood avens?
No feeding required; an annual top-dressing of leaf mould or garden compost in autumn is sufficient to maintain good flowering in lean soils. No feeding required; an annual top-dressing of leaf mould or garden compost in autumn is sufficient to maintain good flowering in lean soils. 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 wood avens?
Half strength is the safe default for wood avens — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding wood avens 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 wood avens 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 wood avens?
Flush the pot of wood avens 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
- Wood Avens care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water wood avens — 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 cobra lily
- How to fertilise pink arisaema
- How to fertilise ginkgo 'fastigiata'
- All 10153 fertilising guides in the Growli library