Scarlet Bidi-Bidi (New Zealand Burr) care

Light

Aim for at least 4-6 hours of direct sun on the leaves. Prefers full sun to very light partial shade. Best foliage colour and burr production occur with maximum sun exposure. In deeper shade, growth becomes sparse and burr development is poor. If your only bright window faces south, that's perfect for scarlet bidi-bidi — same window any aroid would fry on.

Watering

Watering scarlet bidi-bidi: fortnightly once established; drought-tolerant. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Requires very well-drained soil; tolerates dry conditions once established. Water young plants regularly in the first season. Overwatering or waterlogging is the most common cause of decline — this plant thrives on neglect in dry, rocky sites.

Soil and pot

Scarlet Bidi-Bidi grows best in gritty, well-drained, average to poor fertility. Thrives in sandy, gritty, or gravelly soils where drainage is excellent. Does not require fertile soil; overly rich conditions promote lush, floppy growth rather than the tight, compact mat that gives the plant its ornamental appeal. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Scarlet Bidi-Bidi sits happiest at around Low (20–50%) humidity and -15 to 35°C (5 to 95°F). Naturally adapted to open, exposed, dry conditions. Prefers low to moderate humidity; high humidity combined with poor drainage can lead to fungal crown rot. Excellent in exposed, windswept situations. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed scarlet bidi-bidi sparingly. No regular feeding required or recommended. Fertile soils undermine the compact habit. A light top-dressing of grit improves drainage and suits the plant's preference for lean conditions. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on scarlet bidi-bidi in the Growli community. Each is annotated with the most common cause so you know where to start.

• 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.
• Burrs tangling in pet fur and clothing — The spiny burr heads are extremely effective at attaching to fur, wool, and clothing and can cause skin punctures. Locate plants away from lawns and play areas frequented by dogs, or cut off burr heads before they mature.
• Aggressive spread into surrounding plants — Can outcompete smaller alpines and perennials if not monitored. Trim back wandering stems with shears in spring and autumn to keep the mat within bounds.

Propagation

Divide mats in spring by lifting sections with rooted stems and replanting in gritty compost. Stem cuttings root readily in sandy compost in summer. Seed can be sown in autumn in a cold frame; germination is improved by cold stratification. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Scarlet Bidi-Bidi is pet-safe. Acaena microphylla is not listed as toxic by the ASPCA or other authoritative sources, and no toxic compounds have been reported for this genus. The hooked burrs can physically attach to pet fur and cause irritation or skin abrasions if not removed promptly. Not chemically harmful. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Scarlet Bidi-Bidi deep-dive guides

Every aspect of scarlet bidi-bidi care, each with its own calibrated guide:

• Common scarlet bidi-bidi problems & fixes
• Scarlet Bidi-Bidi watering schedule
• Scarlet Bidi-Bidi light requirements
• Best soil mix for scarlet bidi-bidi
• Scarlet Bidi-Bidi fertilizing guide
• When to repot scarlet bidi-bidi
• How to propagate scarlet bidi-bidi
• How to prune scarlet bidi-bidi
• What's eating my scarlet bidi-bidi?
• Scarlet Bidi-Bidi growth rate & size
• Scarlet Bidi-Bidi cold hardiness
• Scarlet Bidi-Bidi temperature & humidity
• Is scarlet bidi-bidi toxic to cats & dogs?
• Is scarlet bidi-bidi toxic to cats?
• Is scarlet bidi-bidi toxic to dogs?
• Getting scarlet bidi-bidi to bloom

Featured in these plant shortlists

Scarlet Bidi-Bidi qualifies for 11 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best pet-safe low-maintenance plants — Non-toxic to cats and dogs and forgiving of forgotten watering — the easiest safe choices for a busy pet household.
• Best pet-safe flowering plants — Flowering houseplants the ASPCA lists as non-toxic to cats and dogs — colour and blooms in a pet home, without the worry.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Scarlet Bidi-Bidi is also known as Scarlet Bidi-Bidi, New Zealand Burr, and Scarlet Piripiri.

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• All 8452 plant care guides in the Growli library