Backyard plant hybridizing

Judith Adam

Updated on:

Helleborus niger 'Praecox' (Photo by Judith Adam)
Helleborus niger 'Praecox' (Photo by Judith Adam)
Helleborus niger ‘Praecox’ (Photo by Judith Adam)

Treasures are revealed as the snow recedes from my front foundation bed. I can see fat buds in the crowns of Lenten hellebores (Helleborus orientalis, syn. H. x hybridus, Zone 5) that are happy in the bright shade on the north side of the house. There’s always a cluster of small, self-sown seedlings around each plant, showing me that hellebores reproduce easily from fresh seed. And that’s the germ of a new idea!

Hellebores are expensive plants, and I want lots of them. My plants were in bloom when they were purchased, so I was able to select colours that I particularly like—dark plum, others pink and yellow, some with spots. I’ve moved their seedlings around the garden and watched the variety of flowers they produce once they’re three or four years old. Some of the flower sepals (hellebores have sepals that look like petals) are muddy greenish tones, but others show flushes of pink. These second-generation flowers are all different, because their parents were randomly fertilized by early spring bees visiting the plants in the front border. It seems to me that gardeners could do as well as, or better than, bees in producing hellebore seedlings with desirable features—and at a great financial saving.

At a website devoted to hellebore information (, I found a page in the hybridizing section with explanatory pictures showing how simple it is to make pollen crosses between plants. If you’d like to develop your own strain of hellebores, you’ll need a magnifying glass, a pair of tweezers, and manicure or embroidery scissors with pointed tips. It’s an easy process, well worth the few minutes of time to move pollen from one plant to another.

First, select your plants for crossing. Plant hybridizing is a complex science, but for backyard gardeners, the most basic rule for producing clear flower tones is to make crosses between blossoms of similar colour. If you want to produce deep plum flowers, plan to breed two plum-coloured plants. Crossing two plants with similar yellow sepals will likely produce seedlings in the yellow to chartreuse range. Pale pink and deeper pink plants will probably produce pink offspring. Of course, you can cross plants of entirely different colours and see what develops; introducing variability in this way could result in a beautiful new shade. There are no guarantees when moving genes around and you might get an unexpected result, perhaps the most beautiful of all your crosses.

Let the more robust of your two plants be the seed-making parent (it will produce more seed), and the smaller or less robust plant be the pollen parent that will contribute its genes. Every hellebore flower has both male and female parts, allowing them to self-fertilize. Using a magnifying glass to look into newly opened flowers on both parent plants, you’ll see many clustered pollen-bearing anthers (the male parts) in the centre, with three to five female styles standing up and above them. Watch the anthers of the pollen plant to see when they extend and open, revealing the ripe grains of yellow pollen inside. The style of the seed parent is ready when its flower is fully open and the styles are prominently standing above the anthers. Using the scissors, cut away the anthers on the seed plant to prevent them from fertilizing the style, and carefully brush them away with a blade of grass or a small leaf. With tweezers, gently grasp a few ripe anthers on the pollen parent and cut them off with the scissors. Take the anthers to your seed parent and rub them on all the sticky tips of the female styles, and the cross is made. You can repeat the process just to be sure of getting enough pollen grains transferred to all the styles.

To keep bees from delivering any further pollen, cover the blossom with a piece of cheesecloth and loosely tie or tape it to enclose the flower head. (You could also just drape it over the entire plant, as light and water will pass through.) Check the flower every few days for seed development. The sepals will begin to lose their bright colour and start fading to green, a sign that seeds are forming. In about two weeks the closed seed capsules will be obvious; remove the cheesecloth to allow further ripening.

Eventually the capsules will open, and seeds will fall around the base of the plant, where they’ll germinate. (You may not notice the seedlings until next spring.) This is more efficient than collecting and growing seed yourself, but if you decide to go this route, plant the seed right away—hellebore seeds need to be planted when fresh to avoid forming long-lasting dormancy.

In two years you can transplant the seedlings around the garden, or pot them up for gifts to friends. This is the easiest and most economical way to increase a collection, and perhaps give the world a fabulous new hellebore with your name on it.

Spring is sprung

Unable to resist checking the status of every living thing, I’ve had an early tour around the garden. Snow has been shrinking from the beds, but still covers much of the lawn. The good news is frost is leaving the ground and there is a small patch of early crocus up. Buds on the Cornelian cherry shrub (Cornus mas) are swelling and showing colour, as well as on the ‘Dawn’ fragrant viburnum (Viburnum x bodnantense ‘Dawn’), and February daphne (Daphne mezereum). If there were to be a day of warm sunshine, these shrubs could begin to open their flowers. I hear cardinals cooing for their mates, and I hope they’ll be nesting here again (they like shrubby landscapes). Life is good in the garden!

Thanks for stopping in at Making a Garden. Come visit me again next week!

Print Friendly, PDF & Email

Leave a Comment