Why Do Hellebore Flowers Last So Long?

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Robert Pavlis

Hellebores are all the rage right now and everybody seems to be adding more to their garden. A big appeal is the fact that they flower so early, sometimes even when there is still snow on the ground. But the real reason people like them is that they bloom a very long time; as much as five months.

Or do they?

They certainly seem to bloom for a long time; a closer look will reveal their secret. Once you understand why they bloom so long you will be able to select other plants that do the same thing.

Why Do Hellebore Flowers Last So Long? This is Helleborus niger, by Robert Pavlis
Why Do Hellebore Flowers Last So Long? This is Helleborus niger, by Robert Pavlis

When is a Flower Not a Flower?

Poinsettia flower, image by Marc Perkins
Poinsettia flower, image by Marc Perkins

When the general public looks at the colorful part of a plant, they call it a flower. Everyone is familiar with a poinsettia and the red part is considered to be the flower, which seems to bloom for many months.

Botanically speaking, the red part is not a flower. By definition a flower is the reproductive structure of the plant, which has organs such as stamens and a pistil, and it is enclosed in an outer envelope of petals and sepals.

Microbe Science for Gardeners Book, by Robert Pavlis

The red part of a poinsettia are bracts (modified leaves), not petals. Inside each structure you will find numerous very small flowers. The petals are almost invisible.

Now lets have a look at a hellebore.

The Hellebore Flower

The picture below is Helleborus niger, from my garden, but the discussion applies to most hellebores including the common hybrids found in gardens. This species that produces very white flowers that look like so many other white flowers, but unlike other flowers, it lasts for months.

Helleborus niger flower
Helleborus niger flower, image by Robert Pavlis

Let’s have a closer look. The white parts are not petals. They are actually sepals, which is the part of the flower you see when it is still in the bud stage.

If you look closer in the center, you can see some familiar structures. You can see the yellow pollen heads from the stamens and in the very center is the pistil.

Around the outside of this is an unusual structure that looks like a small tubular flower. These are nectaries, a modified petal that provide nectar to visiting pollinators.

Nectaries Warm Up the Flower

Hellebore nectaries contain natural yeasts which ferment the nectar. This fermentation produces heat, increasesing the temperature of the nectar and creating a warm micro-climate inside the flower.

Building Natural Ponds book, by Robert Pavlis

Imagine a pollinator finding this warm spot in very early spring. Not only is it a warm place to sit, but a fermented beverage is on tap. No wonder hellebores are frequently pollinated.

Main Part of the Flower Lasts Two Weeks

Most perennial flowers last for one to two weeks and the hellebore is not that different. The picture below is the same flower, two weeks later. The stamens are collapsing – they’ve done their job.

The nectaries (modified petals) are falling off. You can see one sitting on the lower sepal.

Helleborus niger, flower is about 2 weeks old, image by Robert Pavlis
Helleborus niger, flower is about 2 weeks old, image by Robert Pavlis

The pistil seems to be growing, probably because it was fertilized. Over the next few weeks it will get larger and larger as the seeds develop.

The Sepals Are Here to Stay – For a While

The sepals will remain on the plant for several more months and this is why we consider them to flower so long.

Why do they do this?

The sepals are modified leaves and once fertilization takes place they start to photosynthesize. Their color changes to show more green, due to chlorophyll.

The persistent sepals are important for the development and maturation of the seeds, and that is why the plant keeps them. Once the seed is mature, they drop off.

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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

7 thoughts on “Why Do Hellebore Flowers Last So Long?”

  1. I love these these beauties! I think they come from great lineage – some friends think I am weird loving buttercups, etc. but I know I am unique!
    I really like that the sepals remain on the plant open, intact and beautiful for months on end!
    Thank you sharing such great teaching here!

    Reply
  2. Hi Robert. This is interesting; I kind of knew that the ‘flower’ I was admiring wasn’t really a ‘flower’ but it’s nice to have it explained in an understandable way; thank you!
    I have a few nice hellebores in a small bed and am noticing that there are a lot of little babies underneath, this spring. Are they likely all crosses? Can I just let them be, or should I weed some out…?
    Thank you!

    Reply
    • A lot of hellebore seedlings will be crosses. I find seedlings right under the mother plant where they can’t get enough light to grow properly. It is best to move the seedlings to their own spot.

      Reply
  3. Interesting but I’m still wondering how they multiply. DO the seeds blow off and take and grow the next year. Or does the plant spread through underground runners. I seem to have lots of plant where I once had one. And I seem to have others no where near others–across the driveway, out in front when all the original plants were/are in back? I’m not necessarily complaining, just wondering,

    Reply
    • Clumps do get bigger slowly, but I don’t think they spread by runners.

      Once the seed is mature it does fall down. I find most seedlings for the common hydridous right below the mother plant. However for H. foetidus I find the seedlings farther away. I wonder if those are carried by insects.

      Reply
  4. i have a number of helleborus. and a son visiting a few days who could divide them up. does one just put a shovel in and divide say like for hostas or need to be more careful

    Reply
    • Some people say they don’t like to be divided, but I have found the opposite. Divide like any perennial. They seem like real tough plants.

      Reply

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