Bear’s breeches
Botanical Name
Acanthus mollis
Family
Acanthaceae (acanthus)
Also known as
Oyster plant, bear’s foot plant, sea holly
Where is it originally from?
South West Europe and North Africa
What does it look like?
Leafy, erect perennial herb (<1.2 m), with thick roots and large, glossy, strongly lobed, dark green leaves (up to 50 x 30 cm) on long leaf stalks (10-50 cm) growing from the root crown, or on shorter stalks (2-5 cm) growing from the vertical flowering stem. Numerous partly tubular flowers (Oct-April) with one white petal and a large purple 'hood', with purple or brownish veins, are held at the top of the stem in a spike, with lower flowers maturing first. Many dark brown, flattened oval seeds (<1 cm long) are produced in individual capsules (3-4 cm long) from November to May.
Why is it weedy?
Tolerate moderate shade, forms large clumps, and spreads rapidly in disturbed ground, covering large areas.
How does it spread?
Seed is spread by water and birds, and it also spreads by root fragments.
What damage does it do?
Shades out small native plants in shady environments.
Which habitats is it likely to invade?
Riverbanks and roadsides in partial shade and pasture.
What can I do to get rid of it?
1. Physical removal (all year round) - Dig out entire plant - Ensure all plant material is dipsosed of to refuse, burnt or buried deeply to prevent regrowth.
2. Cut and paste - Cut the stem/trunk as close to the ground as possible and cover the entire stump with herbicide as soon as possible after cutting. Apply glyphosate gel (120g/L strength) or metsulfuron gel (10g/L strength) to the entire cut stem.
3. Leaf paint - Brush neat glyphosate (360 g/l) or glyphosate gel on underside of individual leaves on each branch. Ensure herbicide resistant gloves are worn.
4. Foliar spray
Apply either glyphosate (360 g/L active ingredient at 20ml/L knapsack) plus organosilicone penetrant (2ml/L), to cover entire plant. Note: Glyphosate overspray will kill other (desirable) plants.
OR Apply Metsulfuron herbicide (600g/kg active ingredient at 0.5g/1L knapsack or 20g/100L gun and hose) plus organosilicone penetrant (3ml/L) Note: overspray will kill other (desirable) broadleaf plants and has residual activity in the soil which aids in killing below ground parts.
OR triclopyr herbicide (600g/L active ingredient at a 6ml/L) plus organosilicone penetrant (1ml/L). Note: overspray will kill other (desirable) broadleaf plants.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.
What can I do to stop it coming back?
Monitor the site and treat any regrowth from root or seed.
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