Soil & potting mix
Best soil for Scarlet Bidi-Bidi (Acaena microphylla)
Also called Scarlet Bidi-Bidi, New Zealand Burr, Scarlet Piripiri.
More about scarlet bidi-bidi
About Scarlet Bidi-Bidi
Acaena microphylla · also called Scarlet Bidi-Bidi, New Zealand Burr · flowering
Scarlet Bidi-Bidi is a vigorous, carpet-forming perennial from New Zealand grown for its bronze-green finely divided foliage and showy spherical scarlet-red burr heads in late summer. It hugs the ground tightly, making it ideal for rockeries, gravel gardens, and path edges. Very low maintenance once established in a free-draining site.
Preferred mix: Gritty, well-drained, average to poor fertility
Watch for — Crown rot in poorly drained soil: The most common failure: waterlogging in winter causes the crown to rot and stems to die back. Plant exclusively in sharply drained, gritty soil; raise beds if necessary. No recovery once crown rot is established.
Why scarlet bidi-bidi needs this mix
Scarlet Bidi-Bidi flowers hardest in a rich but free-draining loam — fed enough to fuel the display, open enough that the roots never waterlog.
- Flowering is expensive for scarlet bidi-bidi: producing buds, blooms and seed draws heavily on nutrients and steady moisture, so the soil has to keep delivering all season.
- A loam-based mix holds nutrients and water far more evenly than a light peat mix, which means a longer, more reliable flowering period.
- It still needs sharp drainage — most flowering plants resent cold, wet feet far more than they resent being a little lean.
For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.
What goes wrong with the wrong mix
The wrong soil is one of the most common reasons scarlet bidi-bidi struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- A thin, hungry or sandy mix gives scarlet bidi-bidi weak growth and few, short-lived flowers — it simply runs out of fuel.
- A heavy, badly drained soil rots the roots or crown, often over a wet winter, and you lose the plant before it ever flowers again.
- Over-rich, high-nitrogen mixes can push lush leaf at the expense of flowers — balance, not excess, is the aim.
Either starving scarlet bidi-bidi in a thin mix or drowning it in a heavy, badly drained one. It wants the rich-but-free-draining middle, plus a flowering (higher-potassium) feed in season.
pH — does it matter for scarlet bidi-bidi?
Most flowering plants, including scarlet bidi-bidi, do well around pH 6.0-7.0. A cheap soil test is worth it outdoors; one notable exception is any acid-lover (such as some hydrangeas), where pH directly changes flower colour.
If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.
DIY mix vs a bagged one
A quality bagged compost works for scarlet bidi-bidi in pots if you add grit and a flowering feed. In beds, improving the existing soil with compost and ensuring drainage beats any bag.
Drainage and the pot
Free drainage protects the roots and especially the crown over winter — raised beds, grit in the planting hole and never a waterlogged spot. Containers must have a clear drainage hole.
For perennials, refresh the top layer and feed each spring rather than disturbing the roots; for container displays, start with fresh rich mix each season. When the time comes, our repotting guide for scarlet bidi-bidi covers the timing and technique step by step.
Scarlet Bidi-Bidi soil — frequently asked questions
What is the best soil mix for scarlet bidi-bidi?
3 parts good loam or quality peat-free compost : 1 part well-rotted compost or leaf mould : 1 part grit or perlite. Flowering is expensive for scarlet bidi-bidi: producing buds, blooms and seed draws heavily on nutrients and steady moisture, so the soil has to keep delivering all season.
Can I use normal potting soil for scarlet bidi-bidi?
A thin, hungry or sandy mix gives scarlet bidi-bidi weak growth and few, short-lived flowers — it simply runs out of fuel. A quality bagged compost works for scarlet bidi-bidi in pots if you add grit and a flowering feed. In beds, improving the existing soil with compost and ensuring drainage beats any bag.
Does scarlet bidi-bidi need a special pH?
Most flowering plants, including scarlet bidi-bidi, do well around pH 6.0-7.0. A cheap soil test is worth it outdoors; one notable exception is any acid-lover (such as some hydrangeas), where pH directly changes flower colour.
Should I buy a bagged mix or make my own for scarlet bidi-bidi?
A quality bagged compost works for scarlet bidi-bidi in pots if you add grit and a flowering feed. In beds, improving the existing soil with compost and ensuring drainage beats any bag.
How often should I refresh the soil for scarlet bidi-bidi?
For perennials, refresh the top layer and feed each spring rather than disturbing the roots; for container displays, start with fresh rich mix each season. Free drainage protects the roots and especially the crown over winter — raised beds, grit in the planting hole and never a waterlogged spot. Containers must have a clear drainage hole.
Keep reading
- Scarlet Bidi-Bidi care — the full brief (light, water, humidity, problems, pet safety)
- How often to water scarlet bidi-bidi — the schedule the mix feeds into
- Repotting scarlet bidi-bidi — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Should I water my plant? The simple check first
- Why is my plant wilting? Wet vs dry diagnosis
- Root rot — how the wrong soil starts it, and how to save the plant
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- All 8452 soil and potting-mix guides in the Growli library