Should this plant be cut down to ground level in the autumn?
Certified GKH Gardening Expert
I don't recommend handling the plant. If you have to, then wear gloves, as this plant is highly toxic. You don't need to cut them down, but if you do then do it after the growth dies off. Just make sure to dispose of the plant matter to make sure there is no accidental contact with the plant.
Here is an article with more information on their care: https://www.gardeningknowhow.com/ornamental/flowers/monkshood/growing-monkshood-plants.htm