Bulblet fern
Cystopteris bulbifera · Aspleniaceae
Long, narrow, tapering, light green fronds that drape over rocks. Small green bulblets form under the fronds, drop off and grow into new plants.
- Size
- 18 in tall, 18 in wide
- Zones
- 3 to 8
- Light
- Part shade to shade
- Flowers
- Grown for its leaves
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around bulblet fern
The planner designed this bed around bulblet 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 513 that suit those conditions, and says below why bulblet fern stands where it does.
The plants
- 1 Bulblet fern × 8, green leaves
- 2 Blue star creeper × 13, blue
- 3 Polyanthus primrose × 13, yellow
- 4 Turtlehead 'Hot Lips' × 5, pink
- 5 Japanese meadowsweet × 3, pink
- 6 White bleeding heart × 1, white
- 7 Double snowdrop × 12, white
Why this plant
- The only plant grown for its leaves. Leaf lasts all season, where a flower lasts a few weeks.
Why here
- In the middle. At 18 in it is the step between polyanthus primrose (8 in) in front and turtlehead 'Hot Lips' (3 ft) behind: each is seen over the one before.
- A step in the back row. Next to Japanese meadowsweet (3½ ft) and turtlehead 'Hot Lips' (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 8 plants in 2 groups (5 and 3). Seen again further along, the same plant ties the bed together.
Why now
- Here for its leaves, spring to frost. They cover the 10 weeks between early March and late November when nothing on the plan is in flower.
Planned as an English border: 8 of the 8 groups (100%) are drifts, longer along the bed than they are deep. The bed is balanced: the left half carries 52% of the visual weight and the right half 48%. Blue star creeper is planted in four places along the bed, which gives it rhythm.
The planner's own design check: 12 Excellent, 5 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 bulblet fern goes in a border
At 18 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
At its best hanging down a damp, shaded rock face or wall. The dropped bulblets start new plants below, which is a charming way to colonise a wall.
- Draping over shady rocks and walls
- Limestone gardens
- Native woodland planting
What to plant with bulblet fern
Plants recorded as good partners for it, and what each pairing does:
- Wild ginger: bold leaves against its fine ones; low enough (6 in) to stand in front of it; happy in the same moist soil.
- Northern maidenhair fern: happy in the same moist soil.
- Wild columbine: adds the flowers, early May to early June.
Questions about bulblet fern
Does bulblet fern need sun or shade?
Bulblet fern grows in 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 soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.
What zones does bulblet fern grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should bulblet fern be planted?
12 in (30 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 cm), so a group knits into one patch.
It grows 18 in (45 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many bulblet fern plants do I need?
At 12 in apart, set out in staggered rows:
- 12 to fill 10 square feet (about 1 m²)
- 11 for a single row 10 ft (3 m) long
- 38 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used eight in two groups.
Is bulblet 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.
Do deer eat bulblet 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.
Will bulblet fern spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by small bulblets that drop from the fronds and take root. They are easy to pull out where they are not wanted.
What does bulblet fern look like in winter?
Bulblet 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.
In these guides
- Plants for deep shade
- Deer-resistant plants for shade
- Pet-safe plants for shade
- Native plants for shade
- Garden plants native to Canada
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Fern
- Size
- 18 in (45 cm) tall, 18 in (45 cm) wide
- Plant
- 12 in (30 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- None: grown for its foliage
- Leaves
- Fine texture, herbaceous; green
- Shape
- Arching, spreading
- Hardy in
- USDA zones 3 to 8
- Light
- Part shade, shade
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Aspleniaceae
- Comes from
- Canada, U.S.A
- Stands up to
- Deer, 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.