Every year I grow a number of new plants (Helleborus x hybridus) from seed. I do this by deliberately making hybrids. That means that I apply pollen from one plant (the father) to the stigma of the other plant (the mother). As a mother plant I prefer to pick a plant that makes a lot of seed, and has a few characteristics that I would like to see in the offspring. The father plant should have characteristics such as the colour and/or the shape of the flowers.
Obviously I choose healthy plants that grow well.
Hellebores plants self-pollinate. That means that pollen from the flower comes in contact with the stigma of the same flower. This leads to the formation of seed. Bumblebees and bees can also cause this self-pollination, but they can also carry pollen from flowers from one plant to the stigma of flowers of other plants (this is called cross-pollination).
How then can you ensure that pollination of two selected ancestors gives rise to seed? First of all you need: pollen. Use tweezers to pick the ripe stamens from the flower of the father plant and put these in a petri dish. The stamens are ripe in a fully opened flower (pollen will also drop from the flower if you touch it). It is possible to store the pollen in the fridge for a few days. The next step is to find a flower in the mother plant that has just opened or is still closed. This is because the stigma are receptive to pollen one or two days before the pollen in the same flower is ripe. By now applying the collected pollen to the closed flower, for instance with a small brush, the pollination is complete. The applied pollen grains are at an advantage when it comes to the fertilization. In this way, self-pollination is indeed impossible. You don’t have to remove the stamens from the mother plant, but it is possible.
You now have to attach a coloured thread of wool to the pollinated flower. Otherwise in a couple of months you will not know which seed box contains which hybrid. Be sure to take proper notes. In any case, write down the ancestors.
In late April I cover the flower with a bag made of lace curtain. This prevents the seed from falling on the ground when the seed box is ripe, and you will not be able to recover them. Usually ants will run off with the seeds. Also, the bag prevents mice from eating the seed boxes along with the seed.
Sow the seeds in a 4 inch pot filled with John Innes No 1. Cover the seeds with a very thin layer of soil and apply some fine gravel on the surface. This prevents mosses from growing there, and also prevents the washing away of the seeds by watering or by rain.
Place the pot in a sheltered place and starting mid-December, the seeds will germinate. Plant the seedlings carefully, when the first true leaf has appeared. In August the seedlings can go to their final spot, or possibly in a corner of the garden where they can grow for three years. Select the plants with the most beautiful flowers and plant these in the garden.