Sleeping Beauties: In Search of Spring Ephemerals

It’s become a first rite of spring: after the eternity of a northern winter, I head to the woods to find the first sleeping beauties that awake from the forest floor.

To chance upon the powder-soft buds of purple liverworts (Hepatica nobilis) fluttering their long white lashes into flower; or to marvel at the tightly-wrapped cones of bloodroot (Sanguinaria canadensis) that unscroll their virgin-white blooms; or to wander through vast carpets of mottle-leafed trout lily (Erythronium americanum) with downward-cast yellow trumpets as poised as any orchid.

And then, there’s the familiar sight of trilliums (Trillium grandiflorum) raising their white tricorn hats in unison to follow the arc of the sun across the sky.

It’s love at first sight—all over again.

Last spring, in the woodland vales of Mono which I call home, I found exquisite colonies of Dutchman’s breeches (Dicentra cucullaria) growing alongside bursts of yellow trout lilies (Erythronium americanum), emerging stands of blue cohosh (Caulophyllum thalictroides) and circular mounds of wild leek (Allium tricoccum).

Two weeks later, the scene had changed: rare specimens of ruby-coloured Trillium erectum dotted vast sweeps of white trilliums.

This early springtime show is enough to make you believe in magic. But like any good fairytale, there’s a catch. These spring beauties have only two months to live, bloom, become pollinated and set seed before the canopy of trees overhead bursts into leaf to steal their light.

Spring ephemerals have evolved using a precisely timed strategy to ensure their survival.

Interestingly, they are not technically shade lovers. Ephemerals have instead developed a very efficient method of photosynthesis that enables them to accelerate growth in early spring sunlight—well ahead of any other plants on the forest floor. Once the sun is gone, so are they, because unlike full-season woodland perennials, true ephemerals do not thrive in shadier conditions.

Design stratagems

It’s one thing to experience spring ephemerals in nature, but how can we bring their enchantment down to earth in our own gardens? Whether native or exotic, ephemerals thrive in the dappled shade of deciduous trees and under the following conditions.

Ideally, growing environments should mirror the plants’ woodland habitat, with slightly acidic, rich, well-drained soil, mulched with shredded leaf litter.

While ephemerals require moisture during their growth cycle, they are relatively drought-tolerant in their quasi-dormant state. (They are fully dormant for 30 to 90 days, after which time their corms and rhizomes slowly continue to grow into the fall.) In a garden situation, you can extend the season of certain ephemerals simply by providing more moisture. This approach is useful for attractive large-leaved ephemerals such as bloodroot and mayapple (Podophyllum), which normally vanish mid-season.

From a planting design perspective, it’s fairly intuitive to work with ephemerals, especially in a naturalistic way where plants are combined into informal patterns and groups to evoke the feel of a natural environment.

Many ephemerals spread by rhizomes, corms, bulbs or seed to form large colonies, making them ideal temporary fillers between shade plants that last all season long. They can be planted in and around emerging perennials and shrubs where they will fill the gaps in the vegetative layer on the surface of the ground. To create a spontaneous effect, work with randomized patterns, much like you would with flower bulbs.

Another strategy is to plan for season-long succession by pairing spring ephemerals with fall-flowering perennials. For example, plant Virginia bluebells (Mertensia virginica) that bloom in the spring with fall-flowering toad lilies (Tricyrtis) or Japanese anemones (Anemone japonica).

In my previous un-cottage garden, I freely experimented with both stratagems. In the photo above, I planted Prairie shooting star (Dodecatheon meadia) as hidden treasure in a drift of Lady Fern (Athyrium filix-femina var. angustum ‘Lady in Red’). The Dodecatheon goes dormant soon after flowering, disappearing beneath the fronds.

In the shady bed below, I dotted various ephemerals in and amongst later emerging perennials to fill the early gaps in the vegetative ground layer and complement spring bulbs nearby (it also gave me the chance to see how they grew in garden conditions.)

From back left to right, you can see yellow wood poppy (Stylophorum diphyllum), merrybells (Uvularia grandiflora), Virginia bluebells (Mertensia virginica) and bloodroot in the foreground (Sanguinaria canadensis). They’re grouped between a rising trio of Actaea racemosa, Eupatorium rugosa ‘Chocolate’ and Geranium macrorrhizum that will dominate this part of the planting later in the season.

It’s worth knowing that wood poppy self-seeds to excess. Bloodroot also moderately seeds about but its oversize clover-like foliage persists nicely in the deepest shade.

Whichever planting plan you employ, handle ephemerals with extreme care when planting to avoid damage to the corms and roots, which might slow their ability to become established. Best planted in spring or fall, you can divide ephemerals in the autumn by gently digging out the corms, cutting them into pieces and then replanting. Or in the case of Erythronium, you can break apart bulb offsets and replant them. Be sure to use a plant marker to identify them when their leaves disappear.

Beauty with a purpose

Because they’re the first perennials to bloom in the spring, ephemerals provide an early source of nectar that’s valuable to bumblebees, bee flies, green metallic bees and various other flies.

The flowers of ephemerals such as trout lily, mayapple and merrybells (Uvularia) are downward-facing to better serve insects that cruise the forest floor.

After flowering, many ephemerals, such as trilliums, bear seeds with fatty appendages, known as elaiosomes. These attract ants that carry the seeds back to their nests where their young can feed on the elaiosomes, and afterwards the seeds are discarded onto the colony’s garbage heap where conditions are ripe for germination. One ant colony can amass as many as a thousand seeds in a season. All of this happens within a few feet of space, which explains how colonies of ephemerals can expand over time.

Native spring ephemerals

This list includes some borderline spring ephemerals (indicated with *), whose leaves do not necessarily die back and therefore they can be useful as season-long groundcovers or as accent plants in shady woodland gardens.

Bloodroot (Sanguinaria canadensis)*

Blue cohosh (Caulophyllum thalictroides)*

Bunchberry (Cornus canadensis)*

Canada mayflower (Maianthemum canadense)*

Canada violet (Viola canadensis)

Carolina spring beauty (Claytonia caroliniana)

Cut-leaved toothwort (Cardamine concatenata)

Dutchman’s breeches (Dicentra cucullaria)

Jack-in-the-pulpit (Arisaema triphyllum)

Jeweled shooting star (Dodecatheon amethystinum)

Liverwort (Hepatica nobilis var. obtusa)*

Merrybells (Uvularia grandiflora)*

Nodding trillium (Trillium cernuum)

Northern violet (Viola)

Prairie shooting star (Dodecatheon meadia)

Red trillium (Trillium erectum)

Rue anemone (Anemonella or Thalictrum thalictroides)

Squirrel corn (Dicentra canadensis)

Trillium (Trillium grandiflorum)

Trout lily (Erythronium americanum)

Twinleaf (Jeffersonia diphylla)*

Virginia bluebells (Mertensia virginica)

Virginia spring beauty (Claytonia virginica)

Wild leek (Allium tricoccum)

Wood anemone (Anemone quinquefolia var. quinquefolia)

Wood poppy (Stylophorum diphyllum)

Choice Exotic Ephemerals

Natives are not the only option. I consulted with über plant connoisseurs Larry Davidson from Lost Horizons Nursery in Acton and Montreal gardener Barry Parker for their recommendations on exotic ephemerals suitable for Toronto gardens (Zone 6). All selections prefer part sun to shade.

Barry astutely points out that many Asian woodland genera share a common genetic link and habitat preferences with North American species because the continents were connected by a land bridge during the last Ice Age. This opens up a wealth of choices for desirable specimens of genera such as Podophyllum, Trillium and Arisaema. Indeed, it becomes the realm of the collector with holy grails like double-flowered Japanese hepaticas selling for up to 100,000 yen per plant.

Asian twinleaf (Jeffersonia dubia)

This Korean version of our native Jeffersonia produces numerous stalks of upward-facing mauve flowers in early spring, followed by attractive two-lobed leaves. Forms large colonies. 30 cm.

Bittercress (Cardamine nuttallii syn. C. pulcherrima)

A charming western Canadian native ephemeral that’s fully hardy here. Pale pink to light purple with darker veins held on short strong stems. Spreads by rhizomes to form a small mat. 30 cm.

Bloodroot (Sanguinaria canadensis f. multiplex)

This double bloodroot forms handsome clumps in the woodland. Its sterile flowers last much longer than the fertile, single species. 30 cm.

Japanese primrose (Primula sieboldii)

This specimen features soft pubescent leaves and wonderful fringed flowers. Various cultivars offer dazzling colour options. Stoloniferous. 20 cm.

Japanese wood poppy (Hylomecon japonica)

Studded with single, bright yellow four-petalled flowers, this wood poppy has attractive foliage all season long. 30 cm.

True lover’s knot (Paris quadrifolia)

This rhizomatous European woodlander features subtle green cross-shaped foliage and wispy yellow-green flower petals. 25 to 40 cm.

Wood anemone (Anemone nemorosa ‘Vestal’)

A double white form of wood anemone with masses of star-shaped flowers and lacy foliage, it’s both tough and delicate and comprised of bulbs that clump up over time. 15 cm.

Yellow toadshade (Trillium luteum)

This native of the eastern United States is easier to grow than our native T. grandiflorum and features silver and green mottled foliage with lemon-scented yellow flowers. 30 to 45 cm.

Sources:

Read more about ephemerals:

The Explorer’s Garden: Rare and Unusual Perennials by Daniel J. Hinkley, Timber Press, 2009.

Native Plants of the Northeast: A Guide for Gardening & Conservation by Donald J. Leopold, Timber Press, 2005.

Where to buy ephemeral plants in Canada:

Fraser’s Thimble Farm: Rare and Native Plant Nursery, Salt Spring Island, British Columbia

Lost Horizons Nursery, Acton, Ontario

St. Williams Nursery & Ecology Centre, St. Williams, Ontario

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Note: This post was also published in the fall 2015 issue of ‘Trellis’ the magazine of the Toronto Botanical Garden. All photography by Tony Spencer.