Fertilising guide

How to fertilise Catlin's Giant Bugle (Ajuga reptans 'Catlin's Giant')— schedule & NPK

Also called Catlin's Giant Bugle, Giant Bugleweed, Carpet Bugle.

More about catlin's giant bugle

About Catlin's Giant Bugle

Ajuga reptans 'Catlin's Giant' · also called Catlin's Giant Bugle, Giant Bugleweed · flowering

A robust, clump-forming groundcover with oversized, deep bronze-purple leaves and tall spikes of violet-blue flowers in spring. Catlin's Giant is prized for its exceptional leaf size — up to 6 inches — making it one of the boldest Ajuga cultivars. Thrives in partial to full shade and suppresses weeds effectively in moist, humus-rich soil.

Growth habit: Stoloniferous, mat-forming groundcover spreading via runners

What fertiliser catlin's giant bugle actually wants — and why

Catlin's Giant Bugle flowers best on poor soil — feed it and you get a lush leafy plant with very few blooms, the exact opposite of what you want.

Little or nothing. Rich, especially nitrogen-rich, soil pushes foliage at the expense of flowers in this plant — lean ground is the technique, not a deficiency.

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 catlin's giant 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 catlin's giant 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 catlin's giant bugle:

Apply a balanced granular fertiliser (e.g. 10-10-10) in early spring as new growth emerges. A single annual feed is sufficient; over-fertilising promotes lush foliage at the expense of flowers and can encourage crown rot. In practice: no routine feeding at all for catlin's giant bugle — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

The dormant-season rule matters more than the exact interval: skip feeding entirely when catlin's giant 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 catlin's giant bugle

None is the correct answer for catlin's giant bugle. The flower-versus-foliage trade-off is the whole point: hold back and you get the display.

Feeding always goes onto already-damp soil, never dry roots — water catlin's giant bugle first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the catlin's giant bugle watering schedule.

Signs you are over-feeding catlin's giant bugle

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for catlin's giant bugle:

Abundant leafy growth and very few flowers (the classic over-rich symptom).
Soft, floppy stems and a sprawling, leafy habit.
Scorched edges and salt crust if it has been fed in a container.

Signs you are under-feeding catlin's giant bugle

Effectively never an issue — these plants flower on poverty.
Only on genuinely dead soil: weak, thin growth and few blooms.
A short-lived plant in completely spent container compost.

If the symptoms point at watering, light or roots rather than nutrition, the full catlin's giant bugle care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

If catlin's giant bugle has accidentally been fed and is all leaf, a plain-water flush plus a move to leaner soil resets it; otherwise no flushing is needed because you are not feeding it.

Organic vs synthetic feeds for catlin's giant bugle

Organic options

A thin compost mulch for soil structure is the absolute most; mostly, give it nothing. UK/US: leave it lean — no manure, no liquid feed. Poor soil is the active ingredient here.

Synthetic / liquid feeds

None. Synthetic feeds, particularly anything with appreciable nitrogen, directly suppress flowering in catlin's giant bugle.

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 catlin's giant bugle — frequently asked questions

What fertiliser does catlin's giant bugle need?

Little or nothing. Rich, especially nitrogen-rich, soil pushes foliage at the expense of flowers in this plant — lean ground is the technique, not a deficiency. Catlin's Giant Bugle flowers best on poor soil — feed it and you get a lush leafy plant with very few blooms, the exact opposite of what you want.

How often should I feed catlin's giant bugle?

Apply a balanced granular fertiliser (e.g. 10-10-10) in early spring as new growth emerges. A single annual feed is sufficient; over-fertilising promotes lush foliage at the expense of flowers and can encourage crown rot. Apply a balanced granular fertiliser (e.g. 10-10-10) in early spring as new growth emerges. A single annual feed is sufficient; over-fertilising promotes lush foliage at the expense of flowers and can encourage crown rot. In practice: no routine feeding at all for catlin's giant bugle — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

What strength of feed for catlin's giant bugle?