Oxalis – One of Many Shamrocks

Oxalis or Shamrock

Oxalis or Shamrock

As I was browsing the floral department of my local grocery store for fresh tulips, I saw the cutest display of potted “shamrocks” all dressed up for St. Patrick’s Day.  I had to purchase one for my office of course – which, by the way, is already filled with other plants so why not another for the sake of the holiday? I immediately recognized the plant because I have a species of it growing in my back yard, although mine is purple versus green.  It is oxalis.  I suppose I never thought about oxalis having a pure green variety because I’ve mostly been exposed to deep purple oxalis triangularis.  However, the green variety indeed serves as an excellent shamrock, I must say, although I doubt you’ll find a four-leaf clover among its stems.  The word triangularis should give you a clue that the leaves of oxalis are tri-lobed.  I suppose a four-lobed one would indeed be a lucky find in this case . . . Oxalis triangularis purple

Oxalis triangularis

Oxalis triangularis growing in my back yard. March 2016

I’d like to briefly write about the care and attributes of oxalis, but before I do, did you know there is no consensus on which plant is actually considered “the” shamrock? A shamrock is a descriptive term for any one of several clovers, otherwise known as three-leaved plants.   In fact, the word shamrock derives from the Gaelic word seamróg which means “little clover”.    As you can surmise, Irish history and lore are steeped in stories about the shamrock.  Saint Patrick is said to have used the shamrock to describe The Holy Trinity during his mission to Christianize the country.  Centuries-old paintings and stained-glass-adorned churches showing depictions of the shamrock are abundant throughout beautiful Ireland.  In the 18th century, the shamrock moved from being predominately associated with Saint Patrick to becoming the official symbol of Ireland (as is the rose for England).  As such, the Irish have a vested interest in defining exactly what plant is the true shamrock.  Even though, the Irish have not been able to unanimously decide!  Two botanical surveys have been held, one in 1893 and the other in 1988, to attempt to determine the true shamrock of Ireland.  Although Trifolium dubium (lesser clover) was the shamrock with the greatest number of entries in both surveys, there remained four other clovers in the running (including oxalis) as well as were several other tri-leaved species mentioned. All in all, it really doesn’t matter if one clover is designated over another.  When I think of clover I think of spring time Easter bunnies eating away in my childhood backyard.   And as for me now, the vagueness of the shamrock only serves to justify my potted oxalis as a good representative plant for the season!

Oxalis regnellii white

Oxalis regnellii white

Oxalis, sometimes called wood sorrel, is a perennial that does well planted in ground in Zones 6 – 11.  It prefers part shade, with more shade in the southern zones.  Oxalis will die back in the cold of winter but re-sprouts come spring with a flurry of white, pink to light purple flowers depending on the variety you choose to plant.  As mentioned above, the most common oxalis I have seen in ground is the deep purple, oxalis triangularis variety but I understand the green varieties are just as hardy. The plants are relatively low growing, perhaps 9 – 12 inches tall, and look best in the front of beds or mixed with other low growing plants. Flowers are plentiful in the spring and early summer, tapering off during the hottest parts of the year. To plant oxalis, the most reliable method is to obtain divisions from a fellow gardener or purchase rhizomes.  You can attempt seed, but again rhizomes (similar to bulbs) are more reliable if they can be found.  Be sure the plants receive adequate moisture but that the soil drains well.  Soggy areas may promote fungal issues. In my experience, our oxalis hasn’t had to receive a lot of care.  In dry, hot times it tends to wilt or die back a bit, but with added moisture, it perks up rather quickly. Speaking of wilting, an interesting trait of oxalis is it folds, or closes, its leaves at night – so don’t be alarmed if you step out late one evening and find your plant shriveled.  Oxalis is simply one of those plants that is very sensitive to light levels and “sleeps” at night. In addition to planting oxalis in ground, it can be kept as a lovely house plant. Observing the same care as above (bright window with mostly shade – moist, but well-drained soil) you should be able to enjoy Irish shamrocks year ’round.  I plan to do so! Until next time, Cindy

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