Fertilising guide
How to fertilise Woolly yarrow (Achillea tomentosa)— schedule & NPK
Also called Woolly yarrow, Yellow wooly yarrow.
More about woolly yarrow
About Woolly yarrow
Achillea tomentosa · also called Woolly yarrow, Yellow wooly yarrow · flowering
A low-growing, mat-forming yarrow prized for its dense, soft grey-green woolly foliage and cheerful yellow flower heads held above the carpet on short stems. Superb for the front of sunny borders, rock gardens, dry slopes, and paving crevices. Extremely drought-tolerant and heat-resistant once established, it withstands light foot traffic and suppresses weeds effectively.
Growth habit: Low-growing, mat-forming herbaceous perennial; spreading groundcover with woolly silvery-green leaf rosettes
What fertiliser woolly yarrow actually wants — and why
Woolly yarrow 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 woolly yarrow: 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 woolly yarrow, 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 woolly yarrow:
Rarely needed. Lean soils produce the best compact growth. A single light application of balanced granular fertiliser in early spring may benefit plants in very poor substrate, but avoid nitrogen-rich feeds. 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 woolly yarrow 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 woolly yarrow
Half strength is the safe default for woolly yarrow — 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 woolly yarrow first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the woolly yarrow watering schedule.
Signs you are over-feeding woolly yarrow
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for woolly yarrow:
- 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 woolly yarrow
- 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 woolly yarrow care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of woolly yarrow 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 woolly yarrow
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 woolly yarrow — frequently asked questions
What fertiliser does woolly yarrow 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. Woolly yarrow 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 woolly yarrow?
Rarely needed. Lean soils produce the best compact growth. A single light application of balanced granular fertiliser in early spring may benefit plants in very poor substrate, but avoid nitrogen-rich feeds. Rarely needed. Lean soils produce the best compact growth. A single light application of balanced granular fertiliser in early spring may benefit plants in very poor substrate, but avoid nitrogen-rich feeds. 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 woolly yarrow?
Half strength is the safe default for woolly yarrow — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding woolly yarrow 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 woolly yarrow 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 woolly yarrow?
Flush the pot of woolly yarrow 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
- Woolly yarrow care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water woolly yarrow — 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 lonicera x heckrottii
- How to fertilise lonicera caprifolium
- How to fertilise wisteria sinensis
- All 6887 fertilising guides in the Growli library