Fertilising guide

How to fertilise Basil-Leaved Sun Rose (Halimium ocymoides)— schedule & NPK

Also called Basil-Leaved Sun Rose, Portugese Sun Rose.

More about basil-leaved sun rose

About Basil-Leaved Sun Rose

Halimium ocymoides · also called Basil-Leaved Sun Rose, Portugese Sun Rose · flowering

Halimium ocymoides is a compact evergreen shrub in the Cistaceae family native to Portugal and western Spain, named for its small, basil-like dark green leaves with a whitish woolly underside. In late spring to early summer it produces a profusion of bright yellow flowers, each with a bold chocolate-purple basal spot on each petal, creating a striking two-toned display. It demands full sun and sharply drained, poor soil and is one of the most drought-tolerant species in the genus — an excellent choice for dry, Mediterranean-style or gravel gardens. No confirmed ASPCA safety data is available; it is conservatively classified as mildly-toxic for pets.

Growth habit: Compact, bushy evergreen shrub; leaves are small, dark green above and covered in white stellate hairs below, giving a grey-green appearance; flowers in terminal clusters, bright yellow with a distinctive dark basal blotch.

What fertiliser basil-leaved sun rose actually wants — and why

Basil-Leaved Sun Rose is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom.

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 basil-leaved sun rose: 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 basil-leaved sun rose, 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 basil-leaved sun rose:

Avoid fertilising; in exceptionally poor soils apply a very dilute, low-nitrogen feed once in spring to avoid stressing the plant further, but rich feeding reduces hardiness and flowering quality. For a hungry bloomer that means feeding regularly — sparingly through the growing season — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

The dormant-season rule matters more than the exact interval: skip feeding entirely when basil-leaved sun rose 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 basil-leaved sun rose

Follow the flowering-feed label rate for basil-leaved sun rose, or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.

Feeding always goes onto already-damp soil, never dry roots — water basil-leaved sun rose first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the basil-leaved sun rose watering schedule.

Signs you are over-feeding basil-leaved sun rose

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for basil-leaved sun rose:

Lots of lush leaves but few flowers (too much nitrogen).
Scorched leaf edges and salt crust from too-strong or too-frequent feeds.
Soft, sappy growth prone to aphids and mildew.

Signs you are under-feeding basil-leaved sun rose

Sparse, small, short-lived flowers and pale foliage.
A tired plant that stops blooming early in the season.
Weak growth and poor repeat-flowering after the first flush.

If the symptoms point at watering, light or roots rather than nutrition, the full basil-leaved sun rose care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Container-grown basil-leaved sun rose accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.

Organic vs synthetic feeds for basil-leaved sun rose

Organic options

A liquid comfrey or seaweed feed (naturally potassium-rich) plus compost or well-rotted manure as a mulch. UK: comfrey feed, organic Tomorite, or rose feed; US: Espoma Rose-tone or Neptune's Harvest. Feeds and improves soil.

Synthetic / liquid feeds

A high-potash flowering feed on a regular cadence — UK: Tomorite (Levington), Phostrogen or a specialist rose feed; US: Miracle-Gro Bloom Booster or a rose food. Fast, reliable bloom response.

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 basil-leaved sun rose — frequently asked questions

What fertiliser does basil-leaved sun rose need?

A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom. Basil-Leaved Sun Rose is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.

How often should I feed basil-leaved sun rose?

Avoid fertilising; in exceptionally poor soils apply a very dilute, low-nitrogen feed once in spring to avoid stressing the plant further, but rich feeding reduces hardiness and flowering quality. Avoid fertilising; in exceptionally poor soils apply a very dilute, low-nitrogen feed once in spring to avoid stressing the plant further, but rich feeding reduces hardiness and flowering quality. For a hungry bloomer that means feeding regularly — sparingly through the growing season — right through flowering across the main season (spring through early autumn), tapering as blooming ends.

What strength of feed for basil-leaved sun rose?

What does over-feeding basil-leaved sun rose look like?

Lots of lush leaves but few flowers (too much nitrogen). Scorched leaf edges and salt crust from too-strong or too-frequent feeds. Soft, sappy growth prone to aphids and mildew. Using a high-nitrogen general feed on basil-leaved sun rose is the headline mistake — you grow a big leafy plant with few flowers. The second is simply under-feeding a genuinely hungry bloomer and getting a sparse, short display.

Should I flush the soil of basil-leaved sun rose?