- Author: Jutta Thoerner
- Editor: Noni Todd
By Jutta Thoerner UCCE Master Gardener
Size: 4 feet tall (6 feet in bloom) and 3 feet wide
Blooms: 2 feet flower spikes with flattened, hooded, multitoned white to lavender flowers. Blooming time is early spring.
Pruning needs: remove flower stalks after bloom.
Planting Zone: 7-10 USDA
Exposure: partial shade.
Water needs: drought resistant once established
I have several clumps of this perennial in my front yard and I always get the question: what is this? That my visitors don't know the name is understandable, since the common names: bear's breeches or britches, bears foot, oyster plant or sea dock do not describe it well. Acanthus comes from the Greek word “akantha”, translated to spine, a reference to the tall spike that caries the blooms. The large leaves have a rich glossy green and make the plant attractive when not in bloom.
In the spring, Acanthus grows the 2-3 foot spikes that have tubular white to purple flowers. These look a bit like gigantic snapdragons, due to their hooded appearance. Bees and other pollinators love them. I appreciate how long the stalks stay in bloom and that they make a great addition to larger bouquets.
So what does it take to grow Acanthus? The recommended planting zones are zones 7-10. A well-drained soil is a must; they don't like “wet feet”. They appreciate a thick layer of mulch before the colder weather sets in. Plant in partial shade. Mine are under a large tree. They can multiply via rhizomes, and it's recommended that these are planted in contained areas, where they can't spread freely. This has not been a problem in the warmer Paso Robles climate.
Once the plant is established, their water needs are minimal. Be prepared when they go dormant. All leaves dry up and you are left with a clump in the dirt. But as soon as the fall and winter rains come, the beautiful showy leaves reappear. Consider adding this low maintenance and beautiful Acanthus to your garden.
For Gardeners in the cooler parts of our county:
If you'd like to learn more about plants that grow well in the cooler coastal climate, join the UC Master Gardeners for an Open Garden Day at the Victory Garden in Oceano at the Oceano Train Depot and Victory Garden, 1650 Front Street, Oceano, September 3, 2023, from 1:00 – 3:00. This is a free event, and all are welcome. There will be family friendly activities and Master Gardener volunteers will be ready to answer your gardening questions.
Advice to Grow By Workshops
Our next Advice to Grow By Workshop will be September 16th, 2023, at 10:00 to 12:00 p.m. in our Garden of the Seven Sisters Demonstration Garden at 2154 Sierra Way, San Luis Obispo. The topic will be “Turf Replacement-lawn removal and lawn alternatives.” The workshop is free and open to the public. Docents will be available after the workshop until 1:00 pm. If inclement weather, the workshop will be canceled.
You can view workshops on Instagram live at slo mg or visit our You Tube channel at “San Luis Obispo County UC Master Gardeners.”
UCCE Master Gardener Helpline offices:
San Luis Obispo: 805-781-5939 (Monday and Thursday 1:00 to 5:00)
Arroyo Grande: 805-473-7190 (Wednesday 10:00 to 12:00)
Templeton: 805-434-4105 (Wednesday 9:00 to 12:00)