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Plant care

The King Ostrich Fern (Ostrich Fern) care

Matteuccia struthiopteris 'The King'

Also called The King Ostrich Fern, Ostrich Fern, Shuttlecock Fern.

RHS H7USDA 3–7Mildly toxic to petsIndoor 120–180 cm tall (4–6 ft)

Watering rhythm

Medium indirect light (a couple of metres from a window)

Frequent — keep consistently moist; daily in hot spells

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Light

Medium indirect light (a couple of metres from a window)

Soil

Fertile, humus-rich, moisture-retentive soil

Humidity

60–80%

Temp

-30–25°C

Pet safety

Mildly toxic to pets

Mature size

120–180 cm tall (4–6 ft)

Care at a glance

Light

Picture the indirect light an east-facing window gives mid-morning — that's the brightness the king ostrich fern grows fastest in. Prefers dappled or partial shade, mirroring its natural streamside and woodland habitat. Tolerates full shade but produces smaller fronds. Morning sun with afternoon shade is acceptable. Avoid prolonged direct afternoon sun, which scorches fronds and triggers early summer dormancy. You'll know it's right when new leaves come out the same size and colour as the established ones. Smaller, paler new leaves = move closer to the window.

Watering

For the king ostrich fern in the ground or in a bed, aim for frequent — keep consistently moist; daily in hot spells. 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. Matteuccia is a moisture-demanding fern native to stream banks. Keep the root zone evenly and consistently moist throughout the growing season. In hot weather, water daily and mulch heavily to retain moisture. Drought causes fronds to brown and collapse by midsummer. Standing water in winter is acceptable if drainage is present.

Soil and pot

The King Ostrich Fern grows best in fertile, humus-rich, moisture-retentive soil. Deep, rich, slightly acidic to neutral soil (pH 5.5–7.0) with high organic matter content is ideal. Amend clay soils with compost to improve drainage while retaining moisture. Sandy soils need substantial organic matter and mulching. Avoid thin or dry chalk soils. 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

The King Ostrich Fern sits happiest at around 60–80% humidity and -30–25°C (-22–77°F). Naturally grows in high-humidity streamside environments. In garden settings in the UK and northern US, ambient humidity is usually adequate. In drier climates or when grown in containers indoors, supplement with daily misting, pebble trays, or a humidifier. Low humidity accelerates frond browning in summer. 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 the king ostrich fern sparingly. Apply a granular balanced fertiliser (e.g. 10-10-10) to the soil in early spring as new croziers emerge. A second application of compost mulch in midsummer maintains soil fertility and moisture. Avoid high-nitrogen liquid feeds, which push soft, sappy frond growth. 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 the king ostrich fern in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Summer frond browning and collapse — The most common problem, caused by drought or excessive sun. Matteuccia naturally goes partially dormant in hot, dry conditions. Maintain consistent moisture, apply a thick mulch, and position in afternoon shade. Fronds will not recover once browned but new growth returns the following spring.
  • Invasive spreading — 'The King' spreads vigorously via stolons and can colonise large areas rapidly. Install root barriers or grow in large containers sunk into the ground to limit spread. Dig out unwanted stolons and young crowns in autumn.
  • Slug damage to emerging croziers — Young, emerging fiddleheads in spring are highly attractive to slugs and snails. Protect with ferric phosphate slug pellets or copper tape around bed edges. Hand-picking at dusk is effective in small gardens. Damage at this stage ruins both the ornamental and edible crop.

Propagation

Easily propagated by digging and replanting rooted stolons or offsets in early spring or autumn. Each stolon tip with attached roots will establish quickly. Division of the main crown is also straightforward in early spring before new growth emerges. Spore propagation is rarely used for this cultivar. 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

The King Ostrich Fern is mildly toxic to pets. The edible fiddleheads (young croziers) of Matteuccia struthiopteris are safe to eat only when thoroughly cooked — raw or undercooked fiddleheads contain an unidentified heat-labile toxin that can cause food poisoning (nausea, vomiting, diarrhoea). Health Canada and the US FDA advise boiling or steaming for at least 10–15 minutes before consumption. Not individually listed by ASPCA for pet toxicity, but due to the documented human toxicity of raw fronds, the plant should be kept out of reach of pets and small children. 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.

The King Ostrich Fern care — frequently asked questions

What is the common name for Matteuccia struthiopteris 'The King'?

Matteuccia struthiopteris 'The King' is most commonly called The King Ostrich Fern, but it is also known as The King Ostrich Fern, Ostrich Fern, Shuttlecock Fern. The names refer to the same species, so care instructions for The King Ostrich Fern apply identically to anything sold as Ostrich Fern.

How much light does the king ostrich fern need?

The King Ostrich Fern grows best in medium indirect light (a couple of metres from a window). Prefers dappled or partial shade, mirroring its natural streamside and woodland habitat. Tolerates full shade but produces smaller fronds. Morning sun with afternoon shade is acceptable. Avoid prolonged direct afternoon sun, which scorches fronds and triggers early summer dormancy.

How often should I water the king ostrich fern?

Water the king ostrich fern frequent — keep consistently moist; daily in hot spells. Matteuccia is a moisture-demanding fern native to stream banks. Keep the root zone evenly and consistently moist throughout the growing season. In hot weather, water daily and mulch heavily to retain moisture. Drought causes fronds to brown and collapse by midsummer. Standing water in winter is acceptable if drainage is present. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is the king ostrich fern toxic to cats and dogs?

The King Ostrich Fern is mildly toxic to pets. The edible fiddleheads (young croziers) of Matteuccia struthiopteris are safe to eat only when thoroughly cooked — raw or undercooked fiddleheads contain an unidentified heat-labile toxin that can cause food poisoning (nausea, vomiting, diarrhoea). Health Canada and the US FDA advise boiling or steaming for at least 10–15 minutes before consumption. Not individually listed by ASPCA for pet toxicity, but due to the documented human toxicity of raw fronds, the plant should be kept out of reach of pets and small children.

What USDA hardiness zone does the king ostrich fern grow in?

The King Ostrich Fern is rated for USDA zone 3–7 and RHS hardiness H7. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

The King Ostrich Fern deep-dive guides

Every aspect of the king ostrich fern care, each with its own calibrated guide:

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

Related guides

The King Ostrich Fern is also known as The King Ostrich Fern, Ostrich Fern, and Shuttlecock Fern.