Wolfbane or Monkshood is more properly known as (Aconitum Gapellus) and is a delightful and easily grown replacement for the tall spikes of delphinium. If you’ve ever seen this plant, you’ll know that the individual flowers resemble a monk’s hood, so this name is appropriate.
Here is the best guide for growing Monkshood in your garden.
How to Grow Monshood?
Full sun or light shade. This plant will live in the shade, but the flowers get quite floppy with reduced sunlight. They perform best with a minimum of six hours of full sun every day.
I grow mine in rich soil with extra organic matter added; the organic matter ensures a consistent supply of moisture and nutrients that keep this plant sturdy and growing without stakes. I suspect if you overfeed it, you will have to stake it.
In nature, Monkshood is found as a woodland edger – getting protection from the blazing heat of the sun but allowed to get all morning and late afternoon sun it could gather. As a woodland edger, it would also receive the benefits of leaf litter – a constant and even soil moisture and temperature – to encourage it to bloom.
We have to emulate that condition in our gardens if we want to see this plant truly thrive. If you allow the garden soil to dry out, the performance of this plant will suffer. Being an “edger,” you may very well find that Monkshood will do well for your clay soil garden.
I’d suggest you add as much organic matter/leaf litter in the fall to emulate its natural environment but try it if you have clay soils.
If you truly enjoy the blooms of Aconitum, then let me pass along this growing tip. As soon as the blooms are done on the first flowering flush, cut the bloom stalks to the ground and do not allow the plant to set seed. This will encourage it to set another round of flowers later in the summer.
One of the delights of this plant is that it is an early summer bloomer; once it starts to grow, you can watch it explode from the ground to give one of the tallest early displays in the garden.
The variety typically found in garden centers is Aconitum cammarum, and my favorite is Aconitum cammarum’ Bicolor’. It has a blue and white flower and is quite lovely.
‘Blue Sceptre’ with mid-blue flowers and ‘Bressingham Spire’ with a deep lavender purple flower are two other exceptional varieties.
Aconitum carmichaelii is a fall-blooming species that I enjoyed last summer at the Montreal Botanic Gardens; I enjoyed it so much that I obtained seed and started my own. In January, the seed was sown in a cold frame, allowed to freeze and thaw naturally for several months, and I notice that I have a few seedlings starting to germinate right now.
The seeds do require that cold stratification for successful germination.
Aconitum hyemale as a species is seldom grown, but the off-white form of this is sometimes found. Called ‘Ivorine,’ it too blossoms in early summer, and if you need a 48-inch tall white form, I would recommend this one.
Aconitum x hybrida ‘Pink Sensation’ is a new introduction with soft lavender-pink blossoms. Interesting and a good grower in my garden.
Monkshood is Poisonous
This is a poisonous plant – all parts of the plant are toxic if you eat them. Roots may be mistaken for edible roots if left lying around.
Handling the plant itself isn’t a problem, so there is no reason not to grow it in your garden. Just don’t eat it.