Monkshood (Aconitum) also known as wolfsbane and common aconite, is a beautiful, stately perennial with tall spires of purple-blue flowers from mid- to late summer. It looks similar to delphinium, to which it's related. It's a great plant for the middle or back of a cottage or herbaceous border. Its nectar- and pollen-rich flowers are attractive to a range of pollinators, especially bumblebees.
Monkshood is found growing as a wild flower in mountain meadows all over the northern hemisphere. It's named after its hooded flowers, which are said to resemble the cowls of monks.
All parts of the monkshood plant, especially the roots, are poisonous. One of the toxins it contains, aconitine, was used as a poison on spears and arrows in ancient times and was used to kill wolves (hence its other common name, wolfsbane). It's also said that the Romans used monkshood as an execution method. Wear gloves when handling as the toxins can potentially pass through the skin, and on no account ingest any part of the plant, as this can be fatal.
Cultivars of Aconitum napellus and Aconitum carmichaelii are the most widely available monkshoods, some have white or even pink flowers.
How to grow monkshood
For best results, grow monkshood in partial shade, in moist, well-drained soil. An east or west facing spot is ideal. Light soils should be improved with lots of well-rotted organic matter before planting.
Monkshood: jump links
- Planting monkshood
- Caring for monkshood
- Dividing monkshood
- Growing monkshood: problem-solving
- Buying monkshood
- Best monkshood to grow
Where to grow monkshood
For best results, grow monkshood in cool, moist but well-drained soil in partial shade, such as an east or west facing spot. Improve light soils with lots of well-rotted organic matter before planting.
How to plant monkshood
Dig a hole that's wider and the same depth as the rootball. Incorporate plenty of organic matter when planting, and mulch afterwards. Wear gloves when handling.
Caring for monkshood
As monkshoods can reach quite a height, they may need staking to prevent them flopping. There's no need to deadhead monkshood. Cut the spent flowerheads to the ground in autumn. Ensure the soil is kept moist in spring and in dry spells in summer.
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How to divide monkshood
It's a good idea to divide monkshood plants every few years to keep them vigorous – otherwise a gap tends to form in the middle of the plant. The best time to do this is early spring, just as new growth appears. Replant the new clumps around the garden.
Watch Monty Don divide a monkshood plant in this video from BBC Gardeners' World:
Growing monkshood: problem solving
Powdery mildew can be a problem in summer, when a white, powdery coating appears on the leaves. Prune out any affected leaves and keep the plant well watered to prevent it recurring.
Advice on buying monkshood
- Monkshood can be surprisingly hard to track down – you may need to visit a specialist perennial nursery, or order online
- Avoid buying monkshood if your garden is frequented by curious children or pets as all parts of the plant are toxic
Where to buy monkshood online
Varieties of monkshood to grow
Aconitum carmichaelii (Wilsonii Group) 'Kelmscott' – A tall plant with lavender blue blooms – best at the back of a border. It holds the RHS Award of Garden Merit. Height x Spread: 2.5m x 1m
Aconitum carmichaelii (Arendsii Group) 'Arendsii' – rich blue flowers in early and mid autumn. It holds the RHS Award of Garden Merit. H x S: 1.5m x 50cm