Like many popular garden plants, propagating hellebores can be kept as simple or as involved as you like. Should you wish to take the easiest route then you can increase you hellebore stocks by using either division, or by sowing collected seed. If you really want to be really lazy though, simply remove naturally grown seedlings from beneath the parent plant, and pot them on.
However, for those of you who are up for a bit more of a challenge, you also have an opportunity (with some of these species) to enter the secretive world of hand pollination, a particular technique which can open the eyes to a world of possibilities.
Propagating Hellebores by Division
Although a simple method, dividing hellebores is not a subtle one as they have a woody and extensive root system. To begin with, tie the foliage into two even bunches, creating some sort of a gap through the middle of the plant. Not only will this make it easier to see when you are working, these clumps of foliage can also become great, makeshift handles to help with lifting the plant later.
Using a large fork, dig around the perimeter and then lift the entire specimen from the soil as one large root ball, try to keep as much of the root system as intact as possible. When the root-ball is sat solidly on the ground, use a heavy spade split the root-ball evenly through the middle. Alternatively, by using a second fork, you can dig them both - back to back - into the middle of the plant and then levering the fork handles against each other, gently tease the roots apart. The larger the specimen, the more times it can be divided this way. With a little care its possible to divide hellebores at any time of year, but you will get the best results from lifting in either late spring and early autumn.
Propagating Hellebores by Seed.
Experience through years of growing hellebores by seed has shown than a compost mix containing equal parts John Innes seed and an ordinary multi-purpose compost will generally give the best results. However the key to successfully growing hellebores from seed is to sow them when they are as fresh as possible. Once the seeds have been around for a few weeks their germination rate will begin to deteriorate, but leave it for a couple of months and the seed coat hardens requiring you to wait for its natural dormancy period to finish. This can be anytime between 6 and 18 months so you'll need to keep a close eye on the developing seed pods to catch them just right. Collect the seed pods from the parent plant as soon as they begin to split as this will be the earliest time that the seeds can be removed.
Sow your seeds directly into 9cm pots leaving them to rest on the top of the compost. Now gently cover them with a thin layer of washed horticultural grit and leave outside in a warm shaded area. Over the summer period make sure that the compost remains moist but not water-logged. Depending on the variety, the seedlings can begin to show as early as autumn although other species may not appear until the following spring. When growing species hellbores from seed you will need to be aware of Hellebotus vercarius as - rather peculiarly - it will quickly die back after producing only a couple of leaves. This is normal though and after a long second dormant period a vigourous growth of new foliage will return the following autumn. With all hellebores seedlings, even when they are properly in leaf you will still need patience as you are not likely to see their first flowers for at least another couple of years
Below are brief outlines as to which method of propagation works best with which hellebore varieties.
Helleborus orientalis – the Lentern Rose. This is one of the most popular forms of hellebore due to the huge range of colours and flower patterns that can and have been created by hybridization. It is just as easily propagated by division as it is by seed, though using seed is particularly popular due to its ability to hybridize through hand pollination.
Helleborus nigra – the Christmas Rose. This species can be propagated by seed or division as both techniques work well.
Helleborus argutifolius – Corsican Hellebore. The best way to propagate this species plant is by seed, particularly as it manages to self-seed so readily. If you are growing them for yourself rather than commercially, check for the healthiest seedlings growing around the parent plant, and lift them trying to disturb the root system as little as possible. Pot them on into a seed and potting compost and give them a good water to help bind the roots to the new compost.
Helleborus viridis - the Green Hellebore. Something of a required taste, its large, cup-shaped, yellow/green flowers are almost always a point of discussion when in bloom. Again, this species is best propagated by seed
Helleborus foetidus – the Stinking Hellebore. Don’t be put off by its name as this plant has perhaps the most stunning architectural habit of all the hellebores. Once again this species is best propagated by seed as it doesn’t take well to propagation by division.
Helleborus X sternii . This hybrid is a cross between Helleborus argutifolius and Heleeborus lividus. Once again this variety is best propagated by seed.