Redwood Sorrel (Oregon Oxalis) care

Light

Redwood Sorrel is a useful plant for the room nobody else likes — the north-facing hallway, the basement office, the windowless bathroom with the ceiling LED. Thrives in full to deep shade, its native habitat being the floor of coast redwood and Douglas-fir forests where little direct light penetrates. Leaves close and fold in strong light and will scorch under direct sun. A north-facing position or deep canopy shade is ideal. Expect slow growth and pale new leaves; that's the cost of low light, not a sign anything is wrong.

Watering

For redwood sorrel in the ground or in a bed, aim for water every 7–10 days; drought-tolerant once established but performs best with regular moisture. Soak the root zone rather than misting the foliage; deep, less-frequent watering trains roots downward and produces a more drought-resilient plant by mid-season. Prefers consistently moist soil but tolerates seasonal dry spells once established in the right conditions. Mulch with bark or leaf mold to conserve moisture. Avoid prolonged waterlogging, which can cause rhizome rot.

Soil and pot

Redwood Sorrel grows best in humus-rich, moist, well-draining loam; tolerates sandy and clay. Accepts a range of soil textures but performs best in organically rich, consistently moist soil with a slightly acidic to neutral pH (5.5–7.5). Incorporate leaf mold or composted bark at planting for best establishment. 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

Redwood Sorrel sits happiest at around Moderate to high (55–80%) humidity and 4–24°C (39–75°F). Native to the famously humid Pacific coast forest floor. Appreciates the naturally cool, moist air of western coastal gardens. In inland or dry climates, shade and mulching are critical to compensate. If you keep the room above 4–24°C 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 redwood sorrel sparingly. Minimal fertilization needed in humus-rich soils. Top-dress with leaf mold or compost in autumn. In lean garden soils, a light application of balanced slow-release fertilizer in spring supports lush foliage. 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 redwood sorrel in the Growli community. Each is annotated with the most common cause so you know where to start.

• Vigorous spreading — Oxalis oregana spreads aggressively by rhizome and can overwhelm smaller plants in a border. Install root barriers or confine to areas where ground-covering spread is desired.
• Rust, powdery mildew, and leaf spots — Several fungal diseases including rust (orange pustules), powdery mildew, and seed smut affect this species. Improve airflow in dense patches and remove affected foliage promptly.
• Leaf closure and sun stress — Leaves fold shut in bright light as a heat and photodamage response; if leaves do not reopen in shade this signals stress from excessive light exposure. Relocate to a deeper shade position.

Propagation

Extremely easy by division in spring — small rhizome sections with attached leaves root readily in moist, shaded conditions. Replant immediately at shallow depth and keep consistently moist until established. Seed can be sown fresh in autumn but division is far quicker and more reliable. 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

Redwood Sorrel is mildly toxic to pets. ASPCA lists Oxalis species (shamrock plants) as toxic to dogs, cats, and horses due to soluble calcium oxalates. Clinical signs include salivation, vomiting, and in large ingestions, tremors and kidney effects. Leaves have traditional edible use for humans in small amounts (comparable oxalate content to spinach), but individuals with kidney stones, gout, or arthritis should avoid consumption. Keep away from pets. 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.

Redwood Sorrel deep-dive guides

Every aspect of redwood sorrel care, each with its own calibrated guide:

• Common redwood sorrel problems & fixes
• Redwood Sorrel watering schedule
• Redwood Sorrel light requirements
• Best soil mix for redwood sorrel
• Redwood Sorrel fertilizing guide
• When to repot redwood sorrel
• How to propagate redwood sorrel
• How to prune redwood sorrel
• What's eating my redwood sorrel?
• Redwood Sorrel growth rate & size
• Redwood Sorrel cold hardiness
• Redwood Sorrel temperature & humidity
• Is redwood sorrel toxic to cats & dogs?
• Is redwood sorrel toxic to cats?
• Is redwood sorrel toxic to dogs?
• All 6 Oxalis varieties

Featured in these plant shortlists

Redwood Sorrel qualifies for 1 curated Growli shortlist — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best bathroom plants — Humidity-loving houseplants that also cope with lower light — suited to the steamy, often-dim conditions of a typical bathroom.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Redwood Sorrel is also commonly called Redwood Sorrel or Oregon Oxalis.

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