© Janet Davis
Cool, wet
springs may not be to everyone’s liking, but for Caltha palustris, it
makes life all the merrier. For as its
common name implies, boggy, wet conditions are exactly what marsh marigold
likes.
Native both
to Europe and North America in a wide swath from Alaska to Labrador and south
to South Carolina through Nebraska, marsh marigold is one of early spring’s
most welcome sights, usually appearing in May in the Northeast but in April in
milder areas. In England where it was
once used in May Day celebrations, it is known as the king-cup; Americans often
refer to it as cowslip 
(unlike the English version of cowslip which is Primula
veris.)
Marsh marigold has lustrous, bright-green, heart-shaped, basal leaves. Its brilliant yellow, buttercup-like flowers appear on hollow but sturdy branching stems that range from 1-2 feet (30-60 cm) in height. There is a double variety sometimes called ‘Flore-pleno’ but more appropriately, I think, ‘Monstruosa’. (Is it just me or is there something incongruous about what looks like a nosegay of yellow button mums in a naturalistic setting?)
It makes
its home in swamps, beside streams, in suburban ditches and in wet
meadows—anywhere it receives enough moisture during its burst of spring
growth. It’s a good plant for damp
places in lowland hardwood forests where it enjoys the sun before the trees
leaf out. Here, it combines beautifully
with ostrich fern (Matteucia struthiopteris), royal fern (Osmunda regalis) and
interrupted fern (Osmunda claytonia).
But
conditions needn’t stay too mucky, for marsh marigold is a “spring ephemeral”,
dying back to the roots after its bloom season ends, and will survive dryer
(but not parched) conditions in summer. However, in winter, if the crown is
exposed to harsh temperatures without adequate snowcover, marsh marigold is at
risk, therefore benefits from mulching.
A blanket of shredded damp leaves applied in late autumn will protect
it, but remember to uncover the plants early enough to encourage their timely
blooming.
In his excellent book Hedgemaids and Fairy Candles; The Lives and Lore of North American Wildflowers (McGraw-Hill, 1993) -- a library must if you’re a wildflower lover—Jack Sanders tells us about the rich folklore and medicinal history surrounding marsh marigold. “To many a woods-wise farmer, however, the marsh marigold had a more practical value. The shiny, kindney-shaped leaves were gathered young and boiled from ten minutes to an hour, producing greens that some New Englanders would insist are better than spinach and that American Indians had long enjoyed as a vegetable. Boiling, incidentally, removes acrid irritants that could be poisonous and that cause grazing livestock to avoid the plant.”
Once
established, marsh marigold is a spreader.
It can be transplanted but, like all spring ephemerals, this is best
done in summer, after the plant has gone into dormancy. In damp sunny areas where ferns aren’t too
happy, you can combine marsh marigold with water forget-me-not (Myosotis
scorpioides), yellow iris (Iris pseudacorus), Japanese iris (Iris
ensata), big rodgersia (Rodgersia spp.) and Canada anemone (Anemone
canadensis).
If you want
to encourage marsh marigolds in your garden but fear you’re a little too dry,
consider creating an artificial bog by burying polyvinyl chloride (PVC) pond
liner or a pre-formed plastic pond deep enough so it doesn’t come into contact
with plant roots, perforating it to allow some drainage. Fill in with a good,
rich soil amended with lots of organic material. If it’s built in a low-lying spot, moisture will collect there
naturally. Otherwise you may have to
use the hose on a regular basis, or set up a trickle pump from a nearby
pond—beside which, of course, a bog garden is very appropriate.
Adapted from a column originally published in Toronto Gardens