Fertilising guide

How to fertilise Druce's Cranesbill (Geranium × oxonianum)— schedule & NPK

Also called Druce's cranesbill, Oxford cranesbill, hybrid cranesbill.

More about druce's cranesbill

About Druce's Cranesbill

Geranium × oxonianum · also called Druce's cranesbill, Oxford cranesbill · flowering

Geranium × oxonianum is a vigorous hybrid cranesbill (G. endressii × G. versicolor) that arose naturally near Oxford and was first described by G.C. Druce, hence the common name. It forms spreading, semi-evergreen mounds and produces an extremely long succession of funnel-shaped pink flowers — typically deeper pink than G. endressii, with darker veining inherited from G. versicolor — from late spring right through autumn. Its vigour, ground-covering ability, and tolerance of sun or shade make it one of the most useful border perennials available. Considered non-toxic to cats and dogs.

Growth habit: Vigorous, clump-forming and spreading semi-evergreen herbaceous perennial

Watch for — Invasive spreading by self-seeding: This hybrid is highly fertile and can self-seed prolifically, sometimes smothering slower-growing neighbours; deadhead regularly or shear over after flowering to limit volunteer seedlings.

What fertiliser druce's cranesbill actually wants — and why

Druce's Cranesbill 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 druce's cranesbill: 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 druce's cranesbill, 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 druce's cranesbill:

Requires minimal feeding; a light dressing of balanced fertiliser in spring on poor soils is sufficient. Very fertile soil produces excessive leaf growth at the expense of flowers. In practice: no routine feeding at all for druce's cranesbill — 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 druce's cranesbill 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 druce's cranesbill

None is the correct answer for druce's cranesbill. 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 druce's cranesbill first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the druce's cranesbill watering schedule.

Signs you are over-feeding druce's cranesbill

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

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 druce's cranesbill

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 druce's cranesbill care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

If druce's cranesbill 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 druce's cranesbill

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 druce's cranesbill.

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 druce's cranesbill — frequently asked questions

What fertiliser does druce's cranesbill 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. Druce's Cranesbill 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 druce's cranesbill?

Requires minimal feeding; a light dressing of balanced fertiliser in spring on poor soils is sufficient. Very fertile soil produces excessive leaf growth at the expense of flowers. Requires minimal feeding; a light dressing of balanced fertiliser in spring on poor soils is sufficient. Very fertile soil produces excessive leaf growth at the expense of flowers. In practice: no routine feeding at all for druce's cranesbill — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

What strength of feed for druce's cranesbill?