Fertilising guide
How to fertilise Mountain Rimu (Dacrydium bidwillii)— schedule & NPK
Also called Bog Pine, Mountain Pine, New Zealand Mountain Rimu.
More about mountain rimu
About Mountain Rimu
Dacrydium bidwillii · also called Bog Pine, Mountain Pine · flowering
Mountain Rimu is a compact, slow-growing podocarp conifer native to the montane and subalpine zones of New Zealand's North and South Islands. It forms a low, spreading shrub with fine, scale-like leaves. Hardy and moisture-tolerant, it suits cool temperate gardens and rock gardens. It is not on the ASPCA toxic plants list.
Growth habit: Low-spreading, shrubby evergreen podocarp
What fertiliser mountain rimu actually wants — and why
Mountain Rimu 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 rimu: 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 rimu, 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 rimu:
Apply a slow-release ericaceous fertiliser in early spring. Ericaceous (acid-forming) feeds help maintain soil acidity. Avoid over-fertilising as this podocarp is adapted to low-nutrient conditions. 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 rimu 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 rimu
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for mountain rimu. The variable that actually matters is pH, not concentration.
Feeding always goes onto already-damp soil, never dry roots — water mountain rimu first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the mountain rimu watering schedule.
Signs you are over-feeding mountain rimu
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for mountain rimu:
- 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 rimu
- 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 rimu care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush mountain rimu 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 rimu
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 rimu — frequently asked questions
What fertiliser does mountain rimu 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 Rimu 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 rimu?
Apply a slow-release ericaceous fertiliser in early spring. Ericaceous (acid-forming) feeds help maintain soil acidity. Avoid over-fertilising as this podocarp is adapted to low-nutrient conditions. Apply a slow-release ericaceous fertiliser in early spring. Ericaceous (acid-forming) feeds help maintain soil acidity. Avoid over-fertilising as this podocarp is adapted to low-nutrient conditions. 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 rimu?
Follow the ericaceous product's own rate — these are formulated for the plant, so the dilution on the label is right for mountain rimu. The variable that actually matters is pH, not concentration.
What does over-feeding mountain rimu 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 rimu 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 rimu?
Flush mountain rimu 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 Rimu care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water mountain rimu — 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 bird's-nest orchid
- How to fertilise hemlock water dropwort
- How to fertilise bee orchid
- All 11687 fertilising guides in the Growli library