Monkshood offers attractive foliage and towering stalks of flowers.
Lynn Karlin
Similar to its cousin delphinium, monkshood forms beautiful spires of purple or deep-blue flowers.
The blossoms are held above attractive dissected foliage that gives the plant an almost fernlike appearance.
Credit:Lynn Karlin
One of the main reasons to grow this stunning plant is for its deep, rich blue flowers.
Along with the attractive spikes of the blossoms, monkshood’s foliage is quite attractive.
If you are growing monkshood, always wear gloves when handling the plantsand wash your hands thoroughly when finished.
Credit:Judith Watts
Do not plant it in an area where children play or animals roam.
Where to Plant Monkshood
Choose a location carefully.
Once monkshood is planted, it doesn’t like to be moved.
Credit:Bob Stefko
Select a planting area in partial shade, although the plant will tolerate full sun in cool climates.
Its ability to thrive in rocky soil makes it a prime contender for a rock garden.
How and When to Plant Monkshood
Plant nursery-grown monkshood in early spring.
Credit:John Sylvester
The plant is slow to settle in, but an early spring planting might deliver blooms by fall.
Put on protective gloves when handling the plant.
Slide it out of the container delicately; monkshood doesn’t like to be transplanted.
Credit: Karlis Grants
Don’t loosen the thick roots.
Water the monkshood plant.
Sowing monkshood seed is another option, but success is challenging.
Credit:Blaine Moats
In areas with warm climates, monkshood grows best in partial shade or sunny areas that receive afternoon shade.
Soil and Water
An essential requirement for growing monkshood is consistently moistsoil that drains well.
The well-draining soil prevents rot in the plant’s thick roots.
Credit: Greg Ryan
Monkshood also benefits from rich, organic soil that encourages it to put out the lushest growth possible.
Temperature and Humidity
Cool summers and low humidity are a monkshead plant’s preferred environment.
Although it tolerates low temperatures, it doesn’t handle frost well.
Credit: Illustration by Mavis Augustine Torke
Avoidfertilizers that are high in nitrogen.
Cutting the plant back by a third after it blooms sometimes has the same resulta bonus late-season bloom.
After the plant is killed by frost, cut it back to ground level.
Credit: Illustration by Mavis Augustine Torke
See more of our favorite fall garden plants here.
Pests and Problems
Pests don’t bother monkshood much, but diseases can.
Remove the plant from the garden and destroy it.
How to Propagate Monkshood
Monkshood isn’t easy to propagate, but it is possible withdivisionsor seed.
Carefully tease the thick roots apart (don’t forget your gloves!)
until you have two or more divisions.
Handle the plant as little as possible; it doesn’t like to be moved after it is established.
Immediately plant the divisions in well-draining garden soil that has beenamended with compostor other organic matter.
Clean the planting area and work a couple of inches of compost into the soil to improve drainage.
Sow the seeds 6 inches apart and cover them with 1/16 inch of soil.
Spray with water lightly to moisten the soil.
Monitor the area during the winter and water whenever the top inch of soil is dry.
Find more ideas for cool climate perennials here.
Types of Monkshood
Monkshood
Judith Watts
Aconitum napellusblooms in deep purple-blue in late summer.
Plants grow to 5 feet tall.
The sturdy plants typically need no staking unless grown in too much shade.
It grows 4 feet tall.
It grows 4 feet tall.
Monkshood Companion Plants
Astilbe
Astilbebrings a graceful, feathering note to moist, shady landscapes.
In drier sites, however, the leaves will scorch in full sun.
It will spread slowly over time where well-situated.
Most commercially available types are complex hybrids.
Hostas in new sizes and touting new foliage features seem to appear each year.
Some are intensely fragrant.
Hostas are a favorite of slugs and deer.
Toad Lily
No fall garden should be withouttoad lilies.
Some self-seed but not aggressively.
These hard-working plants need a spot in the sun to look their best and provide season-long blooms.
Frequently Asked Questions
Unfortunately, no.
When grown in optimal conditions, these plants live for 10 to 20 years.
Gardeners who divide their plants every few years are guaranteed a limitless supply of monkshood plants.
Aconitum napellus(Monkshood).
National Capital Poison Center
Monkshood, Aconite.
Guide to poisonous plants College of Veterinary Medicine and Biomedical Sciences Colorado State University.
Accessed August 2, 2024. https://poisonousplants.cvmbs.colostate.edu/plant/1.
