Fertilising guide

How to fertilise Cape daisy (Osteospermum ecklonis)— schedule & NPK

Also called Cape daisy, African daisy, South African daisy, Osteospermum.

More about cape daisy

About Cape daisy

Osteospermum ecklonis · also called Cape daisy, African daisy · flowering

Cape daisy is a sun-loving South African subshrub producing large, cheerful daisy flowers with distinctive spoon-shaped petals in white, pink, yellow, orange, and purple, often with a contrasting blue-purple central disc. Flowers close at night and in dull weather. It blooms abundantly in cool seasons and tolerates mild frost, making it a standout for spring and autumn containers.

Growth habit: Bushy, semi-woody subshrub with spreading, branching stems; lance-shaped to spatulate leaves, sometimes toothed; large composite flower-heads (daisy form) on long peduncles

Watch for — Summer dormancy and flower cessation: Cape daisies naturally reduce or stop flowering in high summer temperatures above 28–30°C. This is not a sign of disease. Cut plants back by one-third, reduce feeding, and maintain moderate watering; flowering returns vigorously when temperatures cool in early autumn.

What fertiliser cape daisy actually wants — and why

Cape daisy 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 cape daisy: 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 cape daisy, 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 cape daisy:

The dormant-season rule matters more than the exact interval: skip feeding entirely when cape daisy 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 cape daisy

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

Signs you are over-feeding cape daisy

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

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 cape daisy

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 cape daisy care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

If cape daisy 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 cape daisy

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 cape daisy.

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 cape daisy — frequently asked questions

What fertiliser does cape daisy 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. Cape daisy 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 cape daisy?

Apply a slow-release balanced fertiliser at planting. Supplement with a high-potassium liquid feed (e.g. tomato fertiliser) every 2 weeks during the flowering season. Avoid high-nitrogen feeds which promote leafy growth at the expense of flowers. Reduce feeding in summer dormancy. Apply a slow-release balanced fertiliser at planting. Supplement with a high-potassium liquid feed (e.g. tomato fertiliser) every 2 weeks during the flowering season. Avoid high-nitrogen feeds which promote leafy growth at the expense of flowers. Reduce feeding in summer dormancy. In practice: no routine feeding at all for cape daisy — at most a thin compost mulch for soil structure, never a flowering or nitrogen feed.

What strength of feed for cape daisy?