Acanthus Species, Armed Bear's Breeches, Spiny Bear's Breeches, Oyster Plant

Acanthusspinosus

Family
Acanthaceae (ah-kanth-AY-see-ee)
Genus
Acanthus (a-KANTH-us)
Species
spinosus (spy-NO-sus)
Synonym
Acanthus caroli-alexandri
Acanthus spinosus subsp. spinosissimus
Sun Exposure
Sun to Partial Shade
Foliage
Herbaceous
Textured
Height
36-48 in. (90-120 cm)
Spacing
24-36 in. (60-90 cm)
Hardiness
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)
USDA Zone 11: above 4.5 °C (40 °F)
Danger
Plant has spines or sharp edges; use extreme caution when handling
Bloom Color
Pink
Medium Purple
White/Near White
Bloom Time
Late Spring/Early Summer
Mid Summer
Other Details
Category
Perennials
Water Requirements
Average Water Needs; Water regularly; do not overwater
Foliage Color
Where to Grow
Bloom Characteristics
Bloom Size
Other details
Soil pH requirements
6.1 to 6.5 (mildly acidic)
6.6 to 7.5 (neutral)
7.6 to 7.8 (mildly alkaline)
Patent Information
Non-patented
Propagation Methods
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; sow indoors before last frost
From seed; direct sow after last frost
Seed Collecting
Bag seedheads to capture ripening seed
Regional

This plant is said to grow outdoors in the following regions:

Clovis, California

San Leandro, California

Santa Monica, California

Boise, Idaho

Washington, Illinois

Shawnee Mission, Kansas

Kennebunkport, Maine

Silver Spring, Maryland

Leeds, Massachusetts

Roslindale, Massachusetts

Ludington, Michigan

Boone, North Carolina

Greenville, North Carolina

Cincinnati, Ohio

Columbus, Ohio

Hamilton, Ohio

Springboro, Ohio

Clackamas, Oregon

Sunnyside, Oregon

Haverford, Pennsylvania

Norristown, Pennsylvania

Wilkes Barre, Pennsylvania

Donna, Texas

Fort Worth, Texas

Leesburg, Virginia

Quilcene, Washington

Seattle, Washington

Charleston, West Virginia

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Gardener's Notes:

4
positives
3
neutrals
0
negative
Sort By:
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C
ROSLINDALE, MA | February 2014 | positive

A superb garden perennial that deserves to be better known and more often grown. If it didn't bloom, it would be worth growing for the gl...Read More

J
(Di) Seven Mile, OH (Zone 6b) | June 2011 | positive

Absolutely beautiful, unique plant. The flowers are a very pretty dusky purple with white. This plant has survived extremely cold winters...Read More

B
Leeds, MA (Zone 5b) | June 2010 | positive

It's taken several years but now my plant has produced it's first bloom. Very different plant, it has survived some very cold winters (-20F)

L
Ithaca, NY (Zone 5b) | October 2005 | positive

I was given several starts of this plant 2 years ago and told that it was A.'Mollis'. Of course I found out that it is actually A. 'spin...Read More

S
Springboro, OH (Zone 6a) | April 2005 | neutral

Likes morning sun in zone 6. Well-draining soil is of high importance, and may need a winter mulching in cooler zones. Divide in spring e...Read More

P
(Zone 8b) | September 2004 | neutral

This plant is less common than acanthus mollis. Its leaves are more deeply divided than acanthus mollis. They produce flower stalks that ...Read More

S
Oklahoma City, OK (Zone 7a) | August 2002 | neutral

Bear's Breeches is a relatively uncommon shade perennial that is becoming increasingly available in the nursery trade, prized for its lar...Read More

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