Native to southern Europe and the Mediterranean. Large, deeply lobed, sometimes spiny leaves in clumps to about 3 ft. wide. Bloom in late spring or summer, when foliage clumps send up tall spikes of hooded whitish, rose, or purple flowers beneath spiny green or purplish bracts. Lop off the prickly spikes at after flowers fade.
These tough plants have spreading roots and can become invasive. Give them plenty of room, or confine them with an 8-in.-deep barrier. In dry-summer regions, they will lose their leaves if deprived of moisture in summer, then leaf out again with winter rains; occasional soakings will keep leaves green during hot weather.
To propagate, dig and divide between midfall and early spring. Control snails, slugs. Plants are effective in shade with bamboo and large-leafed ferns but will survive in dry, sunny spots.
This is the most commonly grown species. In bloom it reaches 4–5 ft. high. The spineless leaves to 2 ft. long are deeply lobed and cut. Plants in the Latifolius group have larger leaves and are generally hardier. The foliage of ‘Hollard’s Gold’ is yellow in spring and throughout summer. ‘Summer Beauty’, probably a hybrid with A. spinosus, is more heat-tolerant.Acanthus spinosus
Similar to A. mollis in size, but its leaves are more finely cut and armed with long spines. Foliage is silvery on the true species. Hybrids have bright green leaves and are known as the Spinosissimus group.
Native to Hawaii. Grows to 3–6 ft. tall and wide. Pure yellow, 2–3-in.-wide flowers are pr...
Bushy and open, this heath grows to 2–3 ft. high and wide and has bright green foliage. Summer f...
Clump-forming plants to about 1 1/2 ft. tall (in bloom) and 1 1/2–2 ft. wide; spread by rhizomes...