Rhododendron & Azalea News

Winter Color: Hollies, Hellebores, and Hamamelis
by Donald Hyatt
Potomac Valley Chapter ARS

Introduction

Those of us who struggle through the ice and snow of winter always appreciate a little bit of color in the rhododendron garden. I realize that there are rhododendron cultivars with pigmented foliage, but on cold days when the leaves of most elepidotes are usually curled up and hanging down like icicles, I look to companion plants for color. Some add color interest in their dormant state but others are just precocious and manage push some flowers in late winter which is a pleasant reminder that spring is not far away.

In this article, I will focus on three plant groups: Hollies, Hellebores, and Hamamelis. The berries of Holly trees color up in late fall and continue to provide garden interest until eaten by hungry birds by spring.

Some hellebore varieties, especially Helleborus niger selections, can actually start blooming in late fall here in Virginia and continue through to spring. The bulk of my hellebores which are H. orientalis hybrids will not flower until late winter. The witch hazels, Hamamelis, will provide color at the end of winter, too. I am amazed at how resilient they are to cold and snow.

There are a number of other plants that have winter interest such as shrubs and trees with colorful bark. I mentioned two Japanese Maples with colored bark in an article on Maples and Companion Plants in our November-December 2020 newsletter. 'Bijou' has yellow bark that contrasts so nicely against a backdrop of evergreen trees. 'Beni Kawa' is nearly identical to the Coral Bark Maple, 'Sango Kaku'. Just like the Red Osier Dogwood, Cornus stolonifera, the red branches can look stunning against the snow.

Note: Special Thanks to Linda Derkach who provided some images used in this piece. All other photos were taken by the author.


Ilex x 'Virginia'

Hellebore Blossoms


Hamamelis 'Arnold Promise'
Witch Hazels are unfazed by Cold and Snow

Hollies

The native holly in my region is Ilex opaca and it was growing on our property and widespread in the woods behind my home when my parents built our family home here in McLean, VA, in 1950. The berries gradually change from green to red in autumn and are in full color before Christmas. We always had plenty of branches to cut for holiday decorations. Their colorful berries add interest all winter long to the rhododendron garden and usually remain on the plants until early spring. That is when clouds of Cedar Waxwing birds descend on my garden to clean out the hollies. The flocks winter in the Southeasterm US but migrate north to breeding grounds and my place is one of their annual fast food stops along the way.

I am fortuate that the U.S. National Arboretum is nearby and their Holly Collection is wonderful. Our ARS chapter used to meet there regularly so I enjoyed visiting the Holly Collection prior to meetings to admire the various forms. There are many red-berried varieties with different foliage qualities, and a few yellow-berried selections, too.

Most hollies are "dioecious" which means there are separate male and female plants. The female plant will carry the berries but there must be a male plant nearby to provide insects with the necessary pollen to fertilize the female flowers so they can develop into berries. When buying a holly, it is wise to check with the nursery to find the best pollinator for that plant. There are a few forms like Ilex cornuta 'Burfordii', 'Nellie Stevens', and the 'Foster Holly' that are self-fertile and will set berries without a pollinator.

Selections of the American Holly, Ilex opaca

Red Berries, Narrow Leaves

Red Berries, Wider Leaves

Yellow Berries
Shiny Leaves

Ilex cornuta

Dwarf Burford Holly

'Nellie Stevens'
Variegated Foliage

'Sunny Foster'

'Sunny Foster' at the U.S. National Arboretum

Ilex aquifolium 'Golden Queen'
More Hollies

'Ajax'

'Centennial Girl'

'Scepter'
More Hollies

Ilex attenuata 'Longwood Gold'

Ilex opaca f. xanthocarpum 'Boyce Thompson'

Ilex verticillata   (Deciduous)

Hellebores

Hellebores are great companion plants in a rhododendron garden. They are also deer resistant and anything that is not devoured by those critters is a great addition to my garden. Most hellebores we grow are hybrids that have been raised from seed. Since seed grown plants can vary significantly in flower characteristics, it is usually best to make selections when plants are in bloom. There are a number of nurseries that raise hellebores so our ARS Chapter has arranged chapter field trips in late winter to buy plants in bloom. That way, we know what to expect. I have purchased flats of unbloomed seedlings and made my selections after I saw them bloom. I then gave the others away or put them in the plant exchange. Interestingly, the colorful flower parts of hellebore blossoms are not really petals but are actually sepals. They usually turn greenish as the season progresses and remain on the plant long after the seeds are shed in summer.

Hellebores are primarily native to Europe in the Balkans. They grow in open meadows in places like Bosnia, Croatia, Turkey, and Greece. Many of us were happy to get our first hellebores, and they were rather expensive. Most of them were Helleborus orientalis plants and at first, we were actually pleased to see that they were reseeding in the garden. However, anything that reseeds readily can also become invasive and so it was with my hellebores. Those seedlings were taking over other cherished perennials in the garden, especially some native wildflowers like my trillium species that were growing nearby. One of our members call them "Croatian Kudzu" referring to that invasive vine introduced from Japan that has engulfed many places in the Southeastern United States.

Since then, I have been moving those rogues to more distant places in the garden and have been replacing them with sterile, interspecific hybrids that are being propagated by tissue culture techniques. I particularly like 'Pink Frost' and 'Ivory Prince' which are very well behaved. Many hellebores have downward facing flowers so I tried to plant them on a bank where I could look into the blossoms. I have also tried to select for plants that have upward facing flowers. Some of the newer commercial varieties like 'Anna's Red' and 'Penny's Pink' that have that characteristic and they are sterile, too.

In recent years, I have been focusing on plants with double flowers since they do not reseed that heavily. I am also fond of yellow in the garden so I have been looking for yellow cultivars to add to my collection. I also like the species Helleborus niger which has upward facing white flowers and blooms earlier in the season, often by Christmas. It is called the "Christmas Rose" in many places.

Hellebores are very resilient to cold weather. Extreme cold can harm the flowers and buds if they have expanded too far, but in most cases, the entire plant can be frozen solid, even while in bloom, and can be expected to come back when the weather warms. Plants can look extremely sad on cold mornings when they are frozen and curled down to the ground, covered with ice. They usually look no worse for wear in a few days when the temperature goes back above freezing.

Hellebores do not require much care which for me is always a good thing. When there are a few mild days during the winter, it is wise to "clean up" the typical Orientalis hybrids by removing the foliage of the previous year. It usually looks quite ratty at the end of the winter when the flowers bloom and it will be easier to do that before the new growth emerges. It is not wise to trim back the leaves on some of the other varieties like H. niger selections or those of H. foetedis. They need the leaves.

The Christmas Rose   -   Helleborus niger

Blackthorn Strain

'Jacob'   (Patented Tissue Culture Variety)

Double Form
Singles with Upfacing Flowers

'Anna's Red'

'Penny's Pink'

Seedlings
Yellow Singles

Yellow with Red Blotch

Yellow with Green Center

Yellow with Orange Nectaries
More Singles
'Ivory Prince'       Photo L. Derkach

'Pink Frost'       Photo L. Derkach

'Silver Moon'
Double Hellebores

Double White with Red Spots

Plants frozen with Snow!

Same plants several days later
Red Doubles

Light Red Double

Deep Red Double

Blackish Red Double
More Doubles

Double White

Pale Pink Double

Pink with Spots
More Doubles

Rose Pink

Warm Pink

Pink with Peach Undertones
Just a Few More

Double Yellow

Yellow and Pink Blend

H. foetidus   'Gold Bullion'

Hamamelis   -   Witch Hazels

Witch Hazels, members of the genus Hamamelis, are woody shrubs or small trees that can be easily worked into a rhododendron garden. They are among the first plants to bloom in late winter in my region. There are a number of hybrids that have flowers in shades of yellow, to orange, and red. I am particularly fond of yellow in the garden and have tucked cultivars like 'Arnold Promise' and 'Angelly' in the background in out of the way locations. In late winter when I see that spot of yellow peaking above my frozen rhododendron, I know that spring is not far away. Yellows always show up so well in the late winter garden. I have planted yellow witch hazels, yellow hellebores, and yellow daffodils as part of my tribute to a Robert Frost poem I first read in elementary school:
"Nothing Gold Can Stay"
    Nature’s first green is gold,
    Her hardest hue to hold.
    Her early leaf’s a flower;
    But only so an hour.
    Then leaf subsides to leaf.
    So Eden sank to grief,
    So dawn goes down to day.
    Nothing gold can stay.
We do have a native species in my area, H. virginiana. It has very inconspicuous yellow blossoms and since it blooms in autumn, its small flowers are hidden by the plant's fall foliage. There are a number of winter blooming Hamamelis hybrids that hold onto their fall foliage which can disguise the blooms. They require some extra garden effort to remove those before the blossoms open.


'Angelly'   (branch)

' Angelly'   (flowers)

'Arnold Promise'       Photo L. Derkach
'Primavera'

'Sunburst'

'Orange Peel'   (plant and flower)
'Jalena'
'Diane'
'Livia'
'Antoine Kort'
Yellow Fall Foliage of the native Hamamelis virginiana
on the Blue Ridge Parkway in North Carolina
The inconspicuous flowers of H. virginiana are
typically hidden by the leaves.

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