Fertilising guide
How to fertilise Ugni (Ugni molinae)— schedule & NPK
Also called Chilean guava, Ugni, Murta.
More about ugni
About Ugni
Ugni molinae · also called Chilean guava, Ugni · tropical
Ugni, the Chilean guava, is a compact evergreen shrub bearing small aromatic red berries with a strawberry-like flavour. Hardier than most subtropical fruit, it tolerates light frost and suits sheltered gardens or pots. It likes full sun to part shade, moist but well-drained acidic soil and shelter from cold winds, and forms a neat, slow-growing bush ideal for hedging.
Growth habit: Dense, slow-growing evergreen shrub with small glossy aromatic leaves, dainty pink-white bell flowers and small dark-red berries; naturally bushy and good for low hedging or topiary.
Watch for — Lime-induced chlorosis: Yellowing leaves on alkaline soil because this myrtle dislikes lime; grow in acidic to neutral conditions and use ericaceous feed.
What fertiliser ugni actually wants — and why
Ugni 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 ugni: 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 ugni, 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 ugni:
Feed in spring and early summer with a balanced or ericaceous slow-release fertiliser; a fruit feed or seaweed tonic supports berry set. It is not a heavy feeder, so avoid high-nitrogen products that promote leaf at the expense of fruit. Stop feeding by late summer. 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 ugni 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 ugni
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for ugni. The variable that actually matters is pH, not concentration.
Feeding always goes onto already-damp soil, never dry roots — water ugni first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the ugni watering schedule.
Signs you are over-feeding ugni
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for ugni:
- 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 ugni
- 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 ugni care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush ugni 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 ugni
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 ugni — frequently asked questions
What fertiliser does ugni 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. Ugni 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 ugni?
Feed in spring and early summer with a balanced or ericaceous slow-release fertiliser; a fruit feed or seaweed tonic supports berry set. It is not a heavy feeder, so avoid high-nitrogen products that promote leaf at the expense of fruit. Stop feeding by late summer. Feed in spring and early summer with a balanced or ericaceous slow-release fertiliser; a fruit feed or seaweed tonic supports berry set. It is not a heavy feeder, so avoid high-nitrogen products that promote leaf at the expense of fruit. Stop feeding by late summer. 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 ugni?
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for ugni. The variable that actually matters is pH, not concentration.
What does over-feeding ugni 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 ugni 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 ugni?
Flush ugni 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
- Ugni care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water ugni — 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 monstera
- How to fertilise pothos
- How to fertilise fiddle leaf fig
- All 5561 fertilising guides in the Growli library