Aconitum napellus f. album
(ak-on-EYE-tum  ne-PELL-us  f.  AL-bum)

Family: Rununculaceae

Common name: aconite; monkshood; wolf’s bane; friar’s cap
Zone: 5 – 8
Height: 4 – 5 ft (1.2 – 1.5 m)
Spread: 2 ft (0.6 m)
Aspect: full sun; partial shade
Soil: moist; fertile; well-draining
Water: regular

Description: An herbaceous perennial with an upright growth habit. Large rounded, dark green leaves are deeply lobed. Panicles of hooded white flowers appear mid-summer through autumn. Flowers are composed of 5 petals with the upper one bulging upward to form a hood-like shape.

Special Notes: Native to Europe and temperate regions of Asia. May need staking in exposed position. Few pests or diseases. Used in ancient times until quite recently for deliberate poisoning. Propagation is by fresh seed; division in spring or autumn.

Caution: All parts of the plant are toxic if ingested. Wear gloves when handling. Sap may cause skin irritation on some people. It can also be absorbed through the pores, if left on exposed skin. Thoroughly wash affected area if you come into contact with the sap. Also wash thoroughly should you be handling any part of this plant without protective gloves.

Posted on December 17, 2012;
updated on August 5, 2024

Acanthus spinosus                                  Family: Acanthaceae
(ah-KAN-thus  speen-OH-sus)

Common name: spiny bear’s breeches
Zone: 6 – 9 
Height: 4 – 5 ft (1.2 – 1.5m)
Spread: 3 ft (0.9m)
Aspect: full sun; partial shade
Soil: fertile; moist; well-draining
Water: regular

Description: An herbaceous perennial with a clump-forming habit. Deeply lobed, shiny, deep green leaves have soft spines along edge. Thirty-inch tall (75 cm) spikes of white hooded flowers flushed with a touch of pink and clasped in deep purple calyces gradually open up along the spike starting in mid-summer through into autumn.

Special Notes: Native to the southeast region of Europe, eastern Mediterranean area, western Turkey and northeast region of Italy. Big, bold, beautiful plant. Attracts bees. May want some shade from hot afternoon sun. Be forewarned: plant this species where you would like it to remain because if any bit of root is left behind when plant is moved, it will come again. Propagate by fresh seed; divide in spring or autumn.

In our Zone 7a garden: This species of acanthus performs very well in our garden although its newly emerging leaves will sport a bright orange fungus growth if we have a cold, damp spring. This fungus does not do any damage to the leaves and disappears once the temperatures warm up and the weather dries out a bit.

Acanthus spinosus attracts much attention from our visitors to the garden in the summer for its spectacular display of botanical grandeur. And the bumblebees absolutely love the flowers, madly pushing with their back legs to get their fat, chubby bodies right inside the hooded blossoms.

Warning: Acanthus spinosus is a vigorous grower, quickly expanding its territory in the garden bed. Every three years John has to bring his acanthus back within its boundaries by removing the external stems in an attempt to keep the plant under control.

It is one of those plants that if you leave a piece of root behind, it will quickly reestablish itself. For this reason, as well as the effort needed to keep it restrained in the garden, we do not recommend this plant to the hobby gardener.

Great Plant Pick 2006

Posted on April 14, 2014; updated on August 5, 2024

Acanthus mollis              Family: Acanthaceae
(ah-KAN-thus  MAWL-iss)

Common name: common bear’s breeches
Zone: 7 – 10
Height: 4 – 5 ft (1.2 – 1.5m)
Spread: 3 ft (0.9m)
Aspect: full sun; partial shade
Soil: fertile; moist; well-draining
Water: regular

Description: An herbaceous perennial with a clump-forming habit. Shiny, deep green leaves are jagged-edged. Three-foot tall (90 cm) spikes of white hooded flowers clasped in deep purple calyces gradually open up along the spike starting in mid-summer through into autumn.

Special Notes: Native to the southwest region of Europe and northwest Africa. Big, bold, beautiful plant. Attracts bees. May want some shade from hot afternoon sun. In hot climates, this particular species is likely to go dormant in summer but re-appear when the weather cools. Be forewarned: plant this species where you would like it to remain because if any bit of root is left behind when plant is moved, it will come again. Propagate by fresh seed; divide in spring or autumn.

In our Zone 7a garden: Acanthus mollis is a surprisingly difficult plant to grow in spite of its given common name. According to Larry Hodgson in his book, Perennials for Every Purpose (Rodale 2000) this particular acanthus only grows well in a few specific areas. We must be in one of those tougher regions on the outskirts of its favoured growing range as the one solitary Acanthus mollis plant that continues to survive in our garden never gets above about three feet (90 cm) tall year after year and has never flowered.

Update: This plant is no longer in our garden. 

Posted on April 14, 2013; updated on August 5, 2024