Fertilising guide
How to fertilise Purple Bugle (Ajuga reptans 'Atropurpurea')— schedule & NPK
Also called Purple Bugle, Bronze Bugle, Atropurpurea Bugleweed.
More about purple bugle
About Purple Bugle
Ajuga reptans 'Atropurpurea' · also called Purple Bugle, Bronze Bugle · flowering
A richly coloured cultivar of common bugle with deep bronze-purple foliage that intensifies in sun, making it one of the most ornamental Ajuga selections. Vivid blue flower spikes in spring provide striking contrast against the dark leaves. Invaluable as a weed-suppressing groundcover in shaded borders, slopes, and under deciduous trees.
Growth habit: Low, mat-forming evergreen perennial; stoloniferous with flat rosettes of glossy bronze-purple leaves; upright flower spikes in spring
What fertiliser purple bugle actually wants — and why
Purple Bugle 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 purple bugle: 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 purple bugle, 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 purple bugle:
Light feeding only — apply a balanced slow-release fertiliser in early spring. Excess nitrogen promotes excessive green growth that dilutes the purple colouration. A top-dressing of well-rotted leaf mould or compost in autumn maintains soil structure without over-feeding. 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 purple bugle 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 purple bugle
Half strength is the safe default for purple bugle — 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 purple bugle first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the purple bugle watering schedule.
Signs you are over-feeding purple bugle
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for purple bugle:
- 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 purple bugle
- 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 purple bugle care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of purple bugle 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 purple bugle
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 purple bugle — frequently asked questions
What fertiliser does purple bugle 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. Purple Bugle 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 purple bugle?
Light feeding only — apply a balanced slow-release fertiliser in early spring. Excess nitrogen promotes excessive green growth that dilutes the purple colouration. A top-dressing of well-rotted leaf mould or compost in autumn maintains soil structure without over-feeding. Light feeding only — apply a balanced slow-release fertiliser in early spring. Excess nitrogen promotes excessive green growth that dilutes the purple colouration. A top-dressing of well-rotted leaf mould or compost in autumn maintains soil structure without over-feeding. 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 purple bugle?
Half strength is the safe default for purple bugle — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding purple bugle 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 purple bugle 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 purple bugle?
Flush the pot of purple bugle 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
- Purple Bugle care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water purple bugle — 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 periclymenum 'serotina'
- How to fertilise lonicera x heckrottii
- How to fertilise lonicera caprifolium
- All 8452 fertilising guides in the Growli library