Magical Snowflakes

Snowflakes are magical!  Even after this past winter, I suspect most people will still admit snowflakes have a certain enchanting quality.  However, for some gardeners, snowflakes do not come from the air but from the ground!  Leucojum vernum or Spring Snowflake is among the first of the bulbs to come into bloom, often beginning in February while the ground is still covered beneath an icy blanket (as pictured below in mid-February at Willowwood Arboretum). 

Like a good snowfall, the pendant white flowers thrive in winters chill and continue to bloom well into March!  

Leucojum is a member of the Amaryllidaceae or Amaryllis Family and is a small genus consisting of merely 2 species.  The genus was formally named and described by the Swedish botanist Carl Linnaeus (1707-1778) in 1753, although the name dates back to at least the times of the Greek philosopher Theophrastus (371-287 BC).  Theophrastus was also well recognized as a naturalist and used the name Leucojum to describe Stock plants (presently Matthiola incana) and a white flowered bulb, although the identity of that bulb remains uncertain.  Later, when the German physician and botanist Leonhart Fuchs (1501-1566) wrote the herbal De historia stirpium commentarii insignes (Notable Commentaries on the History of Plants) he used the name to describe the bulb we know as Leucojum vernum.  Linnaeus simply adopted what had become the recognized name for the plant.  The name comes from the Greek Leukos for white and Ion for violet, describing the white flower color and the faint floral fragrance, similar to that of violets.  The species epithet is from the Latin for spring.   

Several years later in 1759, Linnaeus described the second member of the genus named Leucojum aestivum.  The species is from the Latin meaning flowering, ripening or developing in summer.  Hence, it became known as Summer Snowflake.  Filling out the seasons, in 1753 Linnaeus described a late summer and autumn blooming species that he named Leucojum autumnale (pictured below). 

This species is much different in appearance and in 1807 the British botanist Richard Anthony Salisbury (1761-1829) noted these numerous physical differences and suggested switching it to a new genus named Acis.  Although the physical differences were quite noteworthy – including an absence of green or yellow markings on the tepals, a hollow rather than solid flower stem and very slender foliage – splitting this genus met with resistance.  Finally, in 2004 genetic insights were presented on the differences and this species was finally moved from Leucojum to Acis.  Acis was a river in Sicily that vanished following a volcanic eruption.  It was also the name of a  mortal character in a Greek myth, but any connection with the flower remains a mystery!   

Watching Spring Snowflakes push their flowers through a crust of snow, one would never guess the degree of controversy raised within this genus over the past two centuries!  Fortunately, the plants remain unruffled as they provide a snow-like splash of white to the late winter and early spring garden.  Native from France and Germany southeast to the Ukraine and Romania, the flowers of Leucojum vernum often appear 1-2 weeks after the very closely related Galanthus nivalis (Snowdrop).  Interestingly, I have seen the tips of Leucojum foliage appearing through the soil before that of some neighboring Snowdrops yet, the far more expeditious Snowdrops produced their foliage and flowers first!  As pictured in the floral dance below,

each flower bud of Leucojum is initially upright in orientation and protected by a nearly transparent leafy bract or spathe, very similar to Galanthus.  As the bud continues to expand, a seam in the spathe opens (easily seen in the image above right), allowing the bud, subtending round ovary and floral stem to pass through.  Much like Galanthus, the spathe remains above the flower and curls downward, although not as striking as the Shephard’s Crook form found in Snowdrops.  Free of the restrictive spathe, the flower bud gradually becomes more pendant as seen below,

an orientation that provides some protection from the cold, wintery weather.  The flowers mature to a height of 6-10” while the ½” wide, strap-like leaves stretch to 4-6” tall and provide an attractive, deep green backdrop to the flowers.  

Once fully open, the six tepals form a prominent bell-shaped flower, each roughly ¾” in diameter and as long.  When there is no true distinction between the inner petals and the outer leaf-like sepals, the segments are collectively called tepals.  Each overlapping tepal is roughly ½-¾” wide and gracefully flairs outward near the tip.  These six bold tepals give Snowflakes a somewhat bolder presence in the Garden than Snowdrops.  Each tepal draws to a point at the tip which is also marked with a small green marking that matures to yellow, visible from both the outside and inside of the flowers (as seen below).

Clustered within the flower are six bright orange anthers and a central, club-shaped filament.  The filament is all white except for a green band near the tip that surrounds and helps to highlight the comparatively small white central stigma.  Also visible on the inside of the tepals are light green nectar guides that run from the colorful yellow or green markings at the tip to the base to the base of the tepals, helping to direct pollinators to a sugary meal!

Summer Snowflake or Leucojum aestivum bears similar appearing flowers and although it does indeed bloom later than its vernal cousin, the name is misleading since the flowers appear in mid-April into May, not summer!  Native from central and southern Europe, south into the Caucasus and Iran, Summer Snowflake is a much taller plant as compared to its cousin, reaching 12-20” tall when in bloom (pictured below at Longwood Gardens, Kennet Square PA). 

The 1” wide, linear foliage is nearly as tall as the flowers and its deep green color once again provides a nice backdrop to the flowers.  Leucojum aestivum produces pendant, bell-shaped flowers in clusters of 2-5 as opposed to the single flowers of its vernal cousin, yielding an impactful display!  The image at right shows the clusters of several flowers emerging from below the large, translucent spathes.  The tepals have a similar shape to their cousin, with the outwardly flared tip once again coming to a point and marked by a splash of green or yellow.  Owing to its display of larger and more robust flowers, the selection most often sold and planted is ‘Gravetye Giant’ (as seen above).  Introduced by horticulturist William Robinson (1838-1935), he found the plant at his garden in Sussex England, coincidently named Gravetye Mannor!     

Snowflakes are classified as true bulbs.  Bulbs consist of tightly packed layers of modified leaves that store starches, much as you see when an onion is cut open.  I have had great success with planting bulbs of Summer Snowflake, but have far less luck in finding viable bulbs of the Spring Snowflake.  On several occasions the bulbs arrived desiccated and I have heard similar tales from other gardeners.  If finding a good source of bulbs becomes a challenge, I have found transplanting Leucojum vernum in leaf, either during or following bloom to be very successful, providing you have a source of established plants!  In general, both species of Leucojum prefer a moist environment, especially when actively growing.  They thrive along stream banks, moist woodlands or marshy meadows.  In fact, the seed pods of both species are inflated with air, allowing them to float downstream in search of new regions to grow!  At Willowwood Arboretum, Spring Snowflakes are thriving in silty soils at the base of a slope (as pictured below) where the soil is moister. 

I have also seen Summer Snowflake blooming very nicely in a flooded roadside ditch near Mt. Cuba in Delaware.  By contrast, I have also grown Leucojum aestivum for nearly 30 years in the far drier soil beneath an Eastern Red Cedar (Juniperus virginiana) and Black Walnut (Juglans nigra).  The clumps continue to not only bloom beautifully, but have slowly expanded through the production of offsets, showcasing the ease with which this plant can be grown.  

Plants appreciate a near neutral to slightly acidic pH and both are hardy in zones 4-8.  In the woodland garden, Spring Snowflake looks great combined with Christmas Rose (Helleborus nigra) or the expanding, dark purple leaves of Virginia Bluebells (Mertensia virginica).  Summer Snowflakes are fun to naturalize among low growing sedges or pared with the unfurling orange-red foliage of Maidenhair Ferns or white flowers of Dutchman’s Breeches (Dicentra cucullaria)!

Much like their common name implies, when planted in mass these bulbs do appear like freshly fallen flakes of snow, serving to brighten the often-drab late winter garden with a blanket of white!  I first saw the naturalizing mass pictured below from a second-floor window at Willowwood and had to run out for a look.  Carefree and lasting for decades, their beautiful form always pulls me near for a closer look, a true testament to the magical qualities of Snowflakes!

Bruce Crawford  

Manager of Horticulture:  Morris County Parks Commission