Fertilising guide

How to fertilise Rough-leaved Cape Mallow (Anisodontea scabrosa)— schedule & NPK

Also called Rough-leaved Cape Mallow, Rough-leaf African Mallow, Hairy Mallow, Pink Mallow.

More about rough-leaved cape mallow

About Rough-leaved Cape Mallow

Anisodontea scabrosa · also called Rough-leaved Cape Mallow, Rough-leaf African Mallow · flowering

Anisodontea scabrosa is a vigorous, evergreen shrub from the Cape Floristic Region of South Africa, named for its distinctly rough, hairy leaves, and valued for its prolific, small, deep-pink to magenta hibiscus-like flowers produced from spring until the first frost or year-round in warm climates. It is larger and somewhat hardier than its close relative A. capensis, tolerating brief light frosts in a sheltered position, but performing best in USDA zones 8–11 with well-drained soil and full sun. Prune hard in early spring to prevent it becoming woody and bare at the base. No toxic principles are documented for the genus, though it is not formally listed as non-toxic by the ASPCA.

Growth habit: Upright, vigorously branching evergreen shrub with rough, hairy, lobed leaves on woody stems.

What fertiliser rough-leaved cape mallow actually wants — and why

Rough-leaved Cape Mallow 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 rough-leaved cape mallow: 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 rough-leaved cape mallow, 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 rough-leaved cape mallow:

Apply a balanced slow-release fertiliser in spring; avoid high-nitrogen feeds that stimulate leafy growth at the expense of flowers. In practice: no routine feeding at all for rough-leaved cape mallow — 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 rough-leaved cape mallow 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 rough-leaved cape mallow

None is the correct answer for rough-leaved cape mallow. 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 rough-leaved cape mallow first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the rough-leaved cape mallow watering schedule.

Signs you are over-feeding rough-leaved cape mallow

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for rough-leaved cape mallow:

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 rough-leaved cape mallow

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 rough-leaved cape mallow care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

If rough-leaved cape mallow 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 rough-leaved cape mallow

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 rough-leaved cape mallow.

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 rough-leaved cape mallow — frequently asked questions

What fertiliser does rough-leaved cape mallow 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. Rough-leaved Cape Mallow 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 rough-leaved cape mallow?

Apply a balanced slow-release fertiliser in spring; avoid high-nitrogen feeds that stimulate leafy growth at the expense of flowers. Apply a balanced slow-release fertiliser in spring; avoid high-nitrogen feeds that stimulate leafy growth at the expense of flowers. In practice: no routine feeding at all for rough-leaved cape mallow — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

What strength of feed for rough-leaved cape mallow?