Fertilising guide
How to fertilise Mountain crowberry (Empetrum hermaphroditum)— schedule & NPK
Also called Mountain crowberry, Hermaphrodite crowberry, Alpine crowberry.
More about mountain crowberry
About Mountain crowberry
Empetrum hermaphroditum · also called Mountain crowberry, Hermaphrodite crowberry · edible
Mountain crowberry is a hermaphrodite, mat-forming evergreen shrub of boreal forests, alpine heaths, and Arctic tundra. Unlike the dioecious black crowberry, a single plant sets fruit, producing small black berries used in Scandinavian cooking. It is extremely cold-hardy and suited to acidic rock gardens, peat beds, and upland or heathland gardens.
Growth habit: Prostrate, mat-forming evergreen subshrub
Watch for — Alkaline soil intolerance: Mountain crowberry is highly sensitive to alkaline conditions. Yellowing foliage and stunted growth signal elevated pH. Test soil annually; if pH exceeds 6.0, apply soil sulphur, switch to rainwater for irrigation, and top-dress with acidic pine-bark mulch.
What fertiliser mountain crowberry actually wants — and why
Mountain crowberry 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 mountain crowberry: 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 mountain crowberry, 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 mountain crowberry:
Requires minimal feeding. An optional light application of ericaceous slow-release fertiliser in early spring supports berry production. Avoid nitrogen-heavy formulas. Annual mulching with pine bark or composted bracken provides gentle slow nutrition and helps maintain soil acidity. 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 mountain crowberry 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 mountain crowberry
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for mountain crowberry. The variable that actually matters is pH, not concentration.
Feeding always goes onto already-damp soil, never dry roots — water mountain crowberry first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the mountain crowberry watering schedule.
Signs you are over-feeding mountain crowberry
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for mountain crowberry:
- 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 mountain crowberry
- 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 mountain crowberry care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush mountain crowberry 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 mountain crowberry
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 mountain crowberry — frequently asked questions
What fertiliser does mountain crowberry 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. Mountain crowberry 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 mountain crowberry?
Requires minimal feeding. An optional light application of ericaceous slow-release fertiliser in early spring supports berry production. Avoid nitrogen-heavy formulas. Annual mulching with pine bark or composted bracken provides gentle slow nutrition and helps maintain soil acidity. Requires minimal feeding. An optional light application of ericaceous slow-release fertiliser in early spring supports berry production. Avoid nitrogen-heavy formulas. Annual mulching with pine bark or composted bracken provides gentle slow nutrition and helps maintain soil acidity. 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 mountain crowberry?
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for mountain crowberry. The variable that actually matters is pH, not concentration.
What does over-feeding mountain crowberry 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 mountain crowberry 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 mountain crowberry?
Flush mountain crowberry 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
- Mountain crowberry care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water mountain crowberry — 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 sugar snap pea
- How to fertilise telephone pea
- How to fertilise telegraph cucumber
- All 8452 fertilising guides in the Growli library