Wolfsbane (Aconitum lycoctonum) is a member of the monkshood genus and is also known as yellow monkshood. It is native to Europe, and all parts of the plant are very toxic. The name "wolfsbane" arose because of the bygone European use of an extract of the plant to poison wolves. Used as a garden ornamental, wolfsbane features flowers that are cream to pale yellow, depending on the subspecies. The plant is hardy in U.S. Department of Agriculture plant hardiness zones 3 through 7.
Wolfsbane comes back each year from its perennial underground roots and grows 3 feet tall by 2 feet wide. Its flowers appear in July and August, with many elongate, seemingly hooded flowers on a tall flower stalk. The upper part of each flower is shaped like a cylindrical helmet and encloses the rest of the flower. The helmet portion resembled the hood of a monk's robe to early Europeans. Inside the helmet are two stalked, modified petals that contain hollow-spur nectaries that offer a reward to pollinators such as bees. Dark-green, somewhat lobed leaves are at the bottom of the plant, which sprawls somewhat.
Conditions for Growth
Native to moist, mountain meadows and open woodlands, wolfsbane tolerates a wide variety of soil and sunlight conditions. It grows in light-sandy, medium-loamy and heavy-clay soils, and it needs good drainage. Wolfsbane tolerates alkaline, acidic and neutral soils. Its light conditions can vary from partial shade to full sun. Wolfsbane grows best in cool soil conditions. In an area with hot summers, plant it where it doesn't receive midday sun exposure.
Wolfsbane is propagated from its seeds and by division of its roots. Wear waterproof gloves to handle wolfsbane at all stages of its life because skin can absorb toxic compounds from any part of the plant. Sow wolfsbane seeds as soon as they are ripe, placing them in a cold frame where they can be exposed to winter cold under moist conditions. After the seeds germinate in spring, remove the seedlings when they're big enough to handle, which usually is when they have several sets of true leaves. Give each seedling a 4-inch-wide pot, and grow it through the next winter in the cold frame. Then the seedlings can be planted in a garden during their second spring. Lift mature plants in spring or autumn to divide their roots.
A number of toxic alkaloid compounds are in wolfsbane. Eating any part of the plant, even in small quantities, can be fatal. The toxins act on the heart and the digestive system. Poisoning symptoms usually start with tingling, burning and numbing in the mouth and abdomen. Immediate medical care is needed when the plant is eaten. Handling the plant can cause numbness, and picking its leaves can result in its sap on skin and cause symptoms of wolfsbane's effects on the heart for a couple of hours.