Spiny bear's breeches
Acanthus spinosus · Acanthaceae
A hardier bear's breeches with spine-tipped, deeply cut leaves and tall spires of white and purple flowers that last for weeks and dry well.
- Size
- 4 ft tall, 2½ ft wide
- Zones
- 6 to 9
- Light
- Full sun to part shade
- Flowers
- Mid June to late July
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around spiny bear's breeches
The planner designed this bed around spiny bear's breeches when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, part sun. It chose the other plants from the 708 that suit those conditions, and says below why spiny bear's breeches stands where it does.
The plants
- 1 Spiny bear's breeches × 1, white
- 2 Lingonberry × 3, pink
- 3 Leadwort × 12, blue
- 4 Foxglove beardtongue × 5, white
- 5 Gray's sedge × 3, green
- 6 Coral bells 'Georgia Peach' × 3, red leaves
- 7 Spring starflower × 12, blue
- 8 Red spider lily × 7, red
Why this plant
- Nothing here is unique to it. Its leaf, flower shape and colour are all on the plan already. Its case rests on where it stands and when it performs.
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
- In flower for 7 weeks. From mid June to late July.
- Part of the bed's peak. With lingonberry, foxglove beardtongue and Gray's sedge in mid June: 4 kinds at once. No week has more.
Planned as a cottage garden: 27 of the 27 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The flowering is at its height in mid June, with 4 kinds out together. Cool colours (pink and blue) with red as the warm note, and white and green to calm things between them.
The planner's own design check: 13 Excellent, 4 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 spiny bear's breeches 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.
The stiff spires and thistle-like leaves are strong shapes, best set against soft textures such as catmint or grasses. Like its relative it regrows from root pieces, so plant it where it can stay.
- A bold vertical accent in sun or part shade
- Dried flower spikes
- Contrast with soft, mounded plants
What to plant with spiny bear's breeches
Plants recorded as good partners for it, and what each pairing does:
- Catmint 'Walker's Low': in flower together for seven weeks, from mid June; fine leaves against its bold ones; a low mound at the foot of its spires.
- Cranesbill 'Rozanne': in flower together for seven weeks, from mid June; medium leaves against its bold ones; a low mound at the foot of its spires.
- Russian sage: in flower together for three weeks, from mid July; fine leaves against its bold ones; spires rising out of its mound.
Questions about spiny bear's breeches
Does spiny bear's breeches need sun or shade?
Spiny bear's breeches grows in full sun (6 or more hours of direct sun a day), part sun (4 to 6 hours of sun, including some afternoon sun) and part shade (2 to 4 hours of sun, mostly in the morning).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells.
What zones does spiny bear's breeches grow in?
USDA zones 6 to 9. It is hardy to zone 6, which means it survives winter nights down to about 0 °F (−18 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does spiny bear's breeches flower in my zone?
In zone 5 it flowers mid June to late July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 6 | Mid June to late July |
|---|---|
| Zone 7 | Early June to mid July |
| Zone 8 | Early June to mid July |
| Zone 9 | Late May to mid July |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should spiny bear's breeches be planted?
2½ ft (75 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
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 spiny bear's breeches 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 spiny bear's breeches 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 spiny bear's breeches?
Mostly not. NC State lists it as resistant to rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
Will spiny bear's breeches spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by thick roots and regrows from any piece left in the ground. Choose its place carefully.
What flowers after spiny bear's breeches?
Spiny bear's breeches is over by late July. These start as it finishes and carry the same spot on, so it never goes flat:
- Japanese anemone: from mid August to early October, 3 ft tall, to stand in front of it and cover its fading stems.
- Garden phlox: from mid July to early September, 3½ ft tall.
- Tiger lily: from late July to late August, 4 ft tall.
What does spiny bear's breeches look like in winter?
Spiny bear's breeches 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.
More Acanthus
- Bear's breeches Acanthus mollis
In these guides
- Rabbit-resistant plants
- Pet-safe plants for a sunny border
- Pet-safe plants for shade
- Tall perennials and grasses for the back of a border
- Plants with spires: vertical accents
Every fact on record
- Type
- Perennial
- Size
- 4 ft (120 cm) tall, 2½ ft (75 cm) wide
- Plant
- 2½ ft (75 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- Mid June to late July; upright spires; white, purple
- Leaves
- Bold texture, herbaceous; dark green
- Shape
- Mounding, spreading
- Hardy in
- USDA zones 6 to 9
- Light
- Full sun, part sun, part shade
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Acanthaceae
- Comes from
- Europe, Mediterranean
- Stands up to
- Rabbits
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.