Like Deadly Nightshade, Monkshood and Mandrake, Henbane (Hyoscyamus niger) is a plant with a fearsome reputation. Throughout the centuries, it has been used alongside other toxic plants as an anaesthetic, as well as to create a ‘flying brew’ used to induce hallucinations. Something which led to an association with witchcraft during the middle ages. Henbane seeds found in a Viking burial near Fyrkat, Denmark also suggest it could have been the plant responsible for the fabled rage harnessed by Viking berserkers in battle.
Given all of the above, you may wonder why anyone would wish to grow this particular plant? Well, with its large, hairy, lobed leaves and bell-shaped ivory blooms, each sporting an understated but beautiful purple centre, it is an undeniably attractive plant. Brought to Britain in the Middle Ages, and widely naturalised, it does make an interesting addition to the wildlife garden as well as a unique talking point for visitors.
Before going any further, it is worth pointing out that all parts of the Henbane plant are poisonous and should not be handled without gloves.
Henbane can be grown as an annual but, more often than not, is a biennial, forming a rosette of leaves in its first year before flowering and fruiting in its second. It is thought that the annual or biennial nature of a particular plant depends on the seed collected, with seed produced by early flowering plants resulting in annuals and vice versa. Blooming in June of its first year, our plant above falls into the annual bracket.
Annual Henbane tends to reach a smaller size (around 2ft) compared to the hulking biennial plants encountered in the wild; though both are easy to grow providing they are planted in well-draining soil. We’ve had great success growing them in a simple gritty compost.
The plants themselves do require full sun and have a tendency to get rather leggy if not provided with adequate light. That said, we have found success growing Henbane in pots and it has been fairly easy to move them about until happy.
Growing Henbane from seed
Growing Henbane from seed seems fairly straightforward. As they require light to germinate, it is best to sow them on top of the soil, either in trays as above or direct in the garden.
Our first batch of seeds was cold stratified for two weeks in the fridge in autumn 2020, before being placed in an unheated greenhouse throughout the winter. They grew well all season and were planted out in late March. In reality, however, I needn’t have gone through the trouble and have found better results surfacing sowing in May. The plants above should be large enough to plant out come autumn, and will hopefully flower next year.
The young plants transplant well, and we keep them on the drier side until properly established. It does seem easy to overwater this species, believe me.
Henbane is a rare plant in the British countryside, declining remarkably over recent centuries, reportedly due to the use of herbicides. To this end, it is probably best not to collect wild seed if you are lucky enough to have this impressive plant growing in your area. We purchased our seed online and if you are interested in growing this at home, it should be easy to do the same.