A Gardening Journal

Thanksgiving Hellebore

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Bone-chilling weather: perfect time for hellebores to come into bloom.  This is Helleborus niger 'Thanksgiving', which is reported to start flowering at turkey-time.  Mine are just peaking now, perhaps because they're so young that this is their first season of bloom.  The flowers themselves are still young; the prominent patch of yellow stamens will enlarge considerably in the coming days. 

 

As the clump matures and gathers strength, it will bloom as early as it can—but I'm thrilled to have 'Thanksgiving' company even in January. 

 

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The temperatures may be falling into the teens and single digits, but this extraordinary perennial makes a visit outside essential as well as enjoyable.

 

 

Here's how to grow this unique early-Winter-flowering perennial:

 

Latin Name

Helleborus niger  'Thanksgiving'

Common Name

Thanksgiving Hellebore

Family

Ranunculaceae, the Buttercup family.

What kind of plant is it?

Evergreen perennial.

Hardiness

Zones 3 - 8.

Habit

Multi-stemmed and clumping.

Rate of Growth

Medium. 

Size in ten years

A clump a foot across and eight or nine inches tall.

Texture

Medium; the plant doesn't become large enough—and it's not likely you'd have so many clumps of 'Thankgiving' that it would ever bring a textural concern into plantings.  If your field of vision were suddenly restricted to less than a foot tall and wide, then a mature clump of 'Thanksgiving' would have a dense and even heavy texture. 

Grown for

its single white flowers, produced while Fall is sliding ever more steeply into the trough of Winter.  Helleborus niger is usually thought of as starting into bloom in late December.  'Thankgiving' begins—or, at least, shows buds—several weeks earlier.

 

Hellebores are unique in hardy cold-weather bloomers.  I've always assumed that the reason so many flowers of mid-Winter are tiny—think witch hazel, birch, edgeworthia, snowdrops, mahonia, stachyurus, and Winter-flowering honeysuckle and jasmine—is that their small size makes the them more resistant to freezing.  They've got all the necessary structural and functional parts, with that much more of the components of their cells dedicated to the work at hand—and only those.  There aren't big frills or exuberant purely-ornamental flourishes, such as huge petals or long stamens.  In such cold, it's difficult enough to produce the functional parts themselves. 

 

So many of these flowers are bell-shaped, too, with only a small opening.  And they hang downward.  Both strategies would protect the pistil and stamens from cold rain as well as sharp wind.  The interior of those little bells will be—at least comparatively—warmer as well as drier. 

 

Conversely, most big-flowered species, such as daffodils and tulips, don't bloom until Winter is on the wain, and freezes are mild as well as brief. 

 

The only other Winter-flowering plant with truly large flowers is camellia, but it's not hardy in any sense that this New Englander could respect. Helleborus niger flowers are as large as those of some camellias, but are produced in depth of Winter, when Spring is only a fantasy, and in climates where Winter is so severe it gives pause even to natives of Maine or Montreal.  Real Winter, bitter and unrelenting.  Hellebore's only rival for large-flowered bloom in Winter is Eranthis hyemalis, Winter aconite.  But its flowers arrive in March, when the calendar, the day length, and even the weather show that Spring is near.  Eranthis is also in the Ranunculus family, which is unusually gifted at producing plants with antifreeze in their veins.  

 

its hardiness: Provided other cultural conditions—see below—are acceptable, Helleborus niger thrives even in climates with exceptionally stern Winter weather.  Its Zone 3 hardiness means that the plant could handle the worst weather of anywhere in eastern North America south of the Arctic Circle.  Gardening in Lake Placid?  Newfoundland?  If you can shovel the snow away, you'll find your Helleborus niger there to greet you.

Flowering season

A month earlier than typical for the species, whose common name is Christmas rose.

Color combinations

Helleborus niger 'Thanksgiving' goes with everything.

Partner Plants

Neighboring plants can add to your hellebore's display even as they also make its circumstances more congenial.  The branches of deciduous shrubs and trees that are nearby or even overhead can provide welcome shade in the Summer, but full visual exposure in Winter.  Choose them with two attributes in mind, that the shade they provide in warm weather is dappled not dark, and that they aren't so unattractive when leafless as to detract from the hellebore. 

 

Shrubs are trickier because their Summer shade is so much closer to the ground, and so many are multi-stemmed and therefore fairly dense in both branch and leaf.  Those that also provide a Winter display are ideal.  If you took care to thin the shoots of Siberian dogwood, coppiced willows, or box elders—which can otherwise be very wide and dense shrubs—they would be the ultimate. 

 

Shrubs and small trees with wider canopies but few and steeply-ascendant branches or trunks at ground level—especially if they have good Winter interest—save you the trouble of such Spring and Summer thinning.  Tree clethra, stewartia, and Japanese maples are at the top of my list.

 

You can also partner Helleborus niger with lower neighbors or even groundcovers that look presentable in the Winter.  If you take care that its sprawling stems don't smother the hellebore's foliage, a variegated vinca is probably the most reliable; the all-green forms are too high and vigorous.  Green-leaved Ophiopogon japonicus 'Nana' would be a great textural contrast, but poor in terms of colors; better is the black-leaved O. planiscapus 'Nigrescens', as long as it doesn't grow so closely it would compete.

Where to use it in your garden

Helleborus niger is wasted in a location that's difficult to access when Winter is gathering strength.  Site plants where you can easily enjoy them even when the weather has been horrible: near a doorway, along a pathway, or by a terrace.

Culture

Excellent drainage, especially in Winter—but not achieved in soil that's too dry.  Full sun only where the plant wouldn't be stressed by drought.  Dappled shade is safer.

How to handle it:  The Basics

Hellebores should be planted with the same view into the distant misty future that you adopt—or should—when siting peonies.  They resent disturbance and, at least when happy, are permanent.  It's a challenge to supply both the rich soil and the great drainage that are described in the same breath as being essential.  Planting on a slope, no matter how modest, is one solution.  Another is to grow hellebores in raised beds—at the top of a masonry wall, say—or even in winter-hardy containers, provided that neither siting also subjects the plants to drought.

 

The other way to lower the risk of drought stress is to provide some shade.  Pick a location that provides dappled shade all day, or full sun in the morning and solid shade in the afternoon.  Hellebores partner well with deciduous shrubs, whose bare stems can also provide the dappled shade.  See "Partner Plants" above for some possibilities.

 

Sweet soil is the third good idea to strive for.  You could incorporate lots of marble chips into the planting bed; marble is a form of limestone.  Mulching with gravel is always a good idea, because this helps speed surface drainage.  Use marble there, too.

How to handle it: Another option—or two?

Clip any damaged or faded leaves off right to the ground whenever you've got the opportunity.  After a particularly bad Winter, you may want to cut the entire clump to the ground.  Do this before new foliage starts to arise.

Quirks or special cases

None. 

Downsides

Helleborus niger can be fussier than most other hellebores, and is more likely to sputter or even fail if its desired ideals of good drainage but also decent moisture aren't at least approximated.

Variants

H. niger has been far less generous with its cultivars than H. orientalis.  If your hellebore is one of the great many forms with large and luscious flowers that are not white, it's most likely to be H. x hybridus, which can be a mixture of the Asian hellebore, H. orientalis, with almost any other hellebore than H. niger.  Hybrids between orientalis and niger have been one of the unicorns of horticulture; to date 'Snow Queen' and 'Walberton's Rosemary' are the only two that are confirmed.

 

H. niger can hybridize with H. argutifolius, lividus, and x sternii.  'Ruby Glow' has dusty pink flowers and lightly-mottled leaves.  

 

H. niger 'HGC Jacob' is reputed to start into flower even earlier than 'Thanksgiving', and if it had originated in America instead of Germany, could have been named 'Halloween'. 

 

There are only a few H. niger variants that have arisen spontaneously.  'Potter's Wheel' has larger flowers, 'Marion' is double-flowered and 'Praecox' is early-flowering. 

Availability

'Thanksgiving' is, to my knowledge, no longer available, but 'HGC Jacob' is readily available on-line and, occasionally, at retailers.

Propagation

By tissue culture.  Hellebores are notably uninterested in being divided, and you can't root the leaves, either.  They do propagate by seed, but cultivars don't normally come true.

Native habitat

Helleborus niger is native to central Europe: Switzerland, Austria, Slovenia, and northern Italy.  

 
 
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