Fertilising guide
How to fertilise Rose grape (Medinilla magnifica)— schedule & NPK
Also called Rose grape, Showy medinilla, Pink lantern, Philippine orchid, Malaysian orchid.
More about rose grape
About Rose grape
Medinilla magnifica · also called Rose grape, Showy medinilla · flowering
Rose grape (Medinilla magnifica) is a showy tropical shrub from the Philippines grown for cascading pink flower panicles above large ribbed leaves. It demands bright indirect light, warmth above 15C, and consistently high humidity, plus a cool winter rest to rebloom. Not ASPCA-listed, so treat as mildly toxic and keep away from pets.
Growth habit: Evergreen tropical shrub with a semi-woody, somewhat arching frame, thick winged stems and large leathery, deeply ribbed leaves. In late spring to summer it produces spectacular pendulous panicles of pink flowers cradled by showy bracts, giving the grape-cluster look.
Watch for — Leaf scorch: Pale bleached or brown patches on the big leaves come from harsh direct sun. Move to bright filtered light or add light shading.
What fertiliser rose grape actually wants — and why
Rose grape is an acid-loving plant — it can only take up nutrients in acidic soil, so the feed itself matters less than using an ericaceous formula and never liming.
An ericaceous (acidic) fertiliser, formulated to keep the soil pH low and supply iron and trace elements in a form acid-loving roots can absorb. Ordinary feeds and any lime lock out iron and yellow the leaves.
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 rose grape: 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 rose grape, 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 rose grape:
Feed every two weeks from spring to early autumn with a balanced or high-potassium liquid feed diluted to half strength to support flowering. An ericaceous feed suits its acid-loving roots. Stop feeding entirely during the cool winter rest period. In practice: an ericaceous feed in spring as growth resumes, repeated through the main growing months; never apply lime, bonemeal or wood ash, which raise pH.
The dormant-season rule matters more than the exact interval: skip feeding entirely when rose grape 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 rose grape
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for rose grape. The variable that actually matters is pH, not concentration.
Feeding always goes onto already-damp soil, never dry roots — water rose grape first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the rose grape watering schedule.
Signs you are over-feeding rose grape
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for rose grape:
- Brown, scorched leaf margins from too strong or too frequent a dose.
- White salt crust on the soil surface.
- Soft, lush growth that fruits or flowers poorly.
Signs you are under-feeding rose grape
- Yellowing leaves with green veins (iron chlorosis from high pH).
- Weak growth, poor cropping and an overall pale, stressed look.
- Stunted new shoots in spring despite adequate water and light.
If the symptoms point at watering, light or roots rather than nutrition, the full rose grape care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush rose grape with rainwater (not hard tap water, which raises pH) if salts build up; better still, mulch with pine needles or composted bark and water with rainwater to hold the acidity.
Organic vs synthetic feeds for rose grape
Organic options
Composted pine bark, pine-needle mulch, used coffee grounds and an organic ericaceous feed gently maintain acidity. UK: Vitax or Westland Ericaceous; US: Espoma Holly-tone or Dr. Earth Acid Lovers. Slow, soil-improving, hard to overdo.
Synthetic / liquid feeds
A liquid or granular ericaceous feed — UK: Miracle-Gro Ericaceous, Vitax or Westland; US: Miracle-Gro Acid-Loving Plant Food or Espoma Holly-tone. Pair with rainwater and an acidic mulch for it to work.
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 rose grape — frequently asked questions
What fertiliser does rose grape need?
An ericaceous (acidic) fertiliser, formulated to keep the soil pH low and supply iron and trace elements in a form acid-loving roots can absorb. Ordinary feeds and any lime lock out iron and yellow the leaves. Rose grape is an acid-loving plant — it can only take up nutrients in acidic soil, so the feed itself matters less than using an ericaceous formula and never liming.
How often should I feed rose grape?
Feed every two weeks from spring to early autumn with a balanced or high-potassium liquid feed diluted to half strength to support flowering. An ericaceous feed suits its acid-loving roots. Stop feeding entirely during the cool winter rest period. Feed every two weeks from spring to early autumn with a balanced or high-potassium liquid feed diluted to half strength to support flowering. An ericaceous feed suits its acid-loving roots. Stop feeding entirely during the cool winter rest period. In practice: an ericaceous feed in spring as growth resumes, repeated through the main growing months; never apply lime, bonemeal or wood ash, which raise pH.
What strength of feed for rose grape?
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for rose grape. The variable that actually matters is pH, not concentration.
What does over-feeding rose grape look like?
Brown, scorched leaf margins from too strong or too frequent a dose. White salt crust on the soil surface. Soft, lush growth that fruits or flowers poorly. Feeding rose grape an ordinary fertiliser, or growing it in hard tap water / limey soil, is the defining mistake — it triggers lime-induced chlorosis (yellow leaves, green veins) no amount of feeding fixes until the pH comes down.
Should I flush the soil of rose grape?
Flush rose grape with rainwater (not hard tap water, which raises pH) if salts build up; better still, mulch with pine needles or composted bark and water with rainwater to hold the acidity.
Keep reading
- Rose grape care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water rose grape — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 609 fertilising guides in the Growli library