Cinnamon fern
Osmundastrum cinnamomeum · Osmundaceae Popular
A tall vase of green fronds surrounds stiff, upright, cinnamon-brown spore stalks in spring. The fronds turn gold in autumn. It grows in wet, acid soil.
- Size
- 4 ft tall, 3 ft wide
- Zones
- 3 to 9
- Light
- Part sun to shade
- Flowers
- Grown for its leaves
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around cinnamon fern
The planner designed this bed around cinnamon fern when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part shade. It chose the other plants from the 354 that suit those conditions and its wet soil, and says below why cinnamon fern stands where it does.
The plants
- 1 Cinnamon fern × 1, green leaves
- 2 Lingonberry × 11, pink
- 3 Woodland phlox × 3, blue
- 4 Turtlehead 'Hot Lips' × 5, pink
- 5 Gray's sedge × 3, green
- 6 Wild geranium × 3, pink
- 7 Yellow trout lily × 10, yellow
- 8 Fawn lily 'White Beauty' × 12, white
Why this plant
- The only plant grown for its leaves. Leaf lasts all season, where a flower lasts a few weeks.
- A classic partner for turtlehead 'Hot Lips'. Both are on this plan. A pairing gardeners have proved outranks a general rule.
Why here
- Anchors a back corner. At 4 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to Gray's sedge (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- Here for its leaves, spring to frost. They cover the 15 weeks between early March and late November when nothing on the plan is in flower.
Planned as an English border: 6 of the 6 groups (100%) are drifts, longer along the bed than they are deep. Lingonberry is planted in three places along the bed, which gives it rhythm. The most in flower at one time is 4 kinds, in early May.
The planner's own design check: 11 Excellent, 6 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where cinnamon fern goes in a border
At 4 ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft).
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
A plant of three seasons: woolly white croziers, then the cinnamon stalks, then golden autumn fronds. In wet soil it will take sun.
- Wet soil and pond edges
- A large specimen fern
- Spring and autumn interest
What to plant with cinnamon fern
Plants recorded as good partners for it, and what each pairing does:
- Turtlehead 'Hot Lips': adds the flowers, mid August to late September.
- Cardinal flower: adds the flowers, late July to mid September; happy in the same wet soil.
- Marsh marigold: adds the flowers, mid April to early May; low enough (16 in) to stand in front of it; happy in the same wet soil.
Choosing between it and a look-alike? Ostrich fern vs Cinnamon fern.
Questions about cinnamon fern
Does cinnamon fern need sun or shade?
Cinnamon fern grows in part sun (4 to 6 hours of sun, including some afternoon sun), part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light). It is one of the few that also put up with deep shade.
It wants moist to wet soil, rich in organic matter, and plenty of water. It copes with soil that stays wet.
What zones does cinnamon fern grow in?
USDA zones 3 to 9. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should cinnamon fern be planted?
2½ ft (75 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3 ft (90 cm), so a group knits into one patch.
It grows 4 ft (120 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many cinnamon fern plants do I need?
At 2½ ft apart, set out in staggered rows:
- 2 to fill 10 square feet (about 1 m²)
- 5 for a single row 10 ft (3 m) long
- 6 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is cinnamon fern poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like cinnamon fern?
Cinnamon fern is not native to North America. These North American natives come closest to doing its job:
- Wallich's wood fern: the same job in a bed and the same size; wants moist soil.
- Interrupted fern: the same job in a bed; 8 in shorter, wants moist soil.
- Ostrich fern: the same job in a bed; 6 in wider.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat cinnamon fern?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What does cinnamon fern look like in winter?
Cinnamon fern dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is cinnamon fern good for bees and butterflies?
Cinnamon fern is visited by songbirds.
In these guides
- Plants for deep shade
- Plants for wet soil and rain gardens
- Deer-resistant plants for shade
- Pet-safe plants for shade
- Plants that feed garden birds
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Fern
- Size
- 4 ft (120 cm) tall, 3 ft (90 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- None: grown for its foliage
- Leaves
- Medium texture, herbaceous; green
- Shape
- Vase-shaped, clumping
- Hardy in
- USDA zones 3 to 9
- Light
- Part sun, part shade, shade
- Soil
- Rich, moist to wet
- Water
- High
- Feeding
- None needed
- Family
- Osmundaceae
- Attracts
- Songbirds
- Stands up to
- Deer, wet soil, deep shade
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.