Give acanthus full sun to ensure the best-looking foliage and flowers and to prevent any foliar diseases like powdery mildew. However, in warmer climates, this perennial can struggle in the hot afternoon sun and would benefit from planting in part shade. While you may sacrifice a few flowers in part sun, the plants will perform much better. Acanthus will spread aggressively by sending up new shoots from its creeping roots. Because of its large size, acanthus can easily outgrow smaller, more delicate plants and can be difficult to control. When digging it up, if there are any small pieces of roots left in the soil, they can become new plants. One trick to help keep it under control is to plant acanthus in a bottomless container in the ground so the roots can keep growing outward.
More Varieties of Acanthus
Spiny Bear’s Breeches
Acanthus spinosus is the hardiest type. It has white flowers with purple hoods on plants up to 4 feet tall. Zones 4-9
Common Bear’s Breeches
Acanthus mollis grows to 5 feet tall and produces glossy green leaves and purplish flower stems with mauve-hooded white flowers. Zones 6-10
Balkan Bear’s Breeches
Acanthus hungaricus bears white or light pink flowers with purple bracts on 2-foot-tall stems in early to midsummer. Zones 6-9
Acanthus Companion Plants
Balloon Flower
The inflated buds of balloon flowers are fun to pop. And they make great cut flowers. Cut them in the bud stage, and sear the base of the stems to prevent the milky sap from seeping out and fouling the water. Most commonly available in blue-violet, balloon flowers also come in pink and white, as well as shorter forms that are better suited for rock gardens and containers. In fall, the foliage of balloon flower turns clear gold, so don’t cut the plant down too early or you’ll miss the show! They tolerate light shade, but not wet feet or drought.
Pearly Everlasting
Pearly everlasting is often grown as a flower for drying, but it’s so pretty growing fresh in the garden, it’s hard to bring yourself to cut it and bring it indoors. This North American native looks great even in the driest of weather. Its silvery foliage and creamy white blooms make it suitable for moon or white gardens. Grow it in lean soil or divide it frequently to keep it from spreading too quickly.
Spurge
There are hundreds of different spurges, and most are valued by gardeners because they’re drought-resistant and almost always ignored by deer and rabbits. Spurges are surefire picks for adding color to the garden. Many also turn gorgeous colors in the fall, enlivening the fall garden.
