The ‘real’ shamrock for St. Patrick’s Day

Once in a while it is nice to pay tribute to a plant that really only gets recognition one day of the year - the shamrock.

oxalis acetosella

Once in a while it is nice to pay tribute to a plant that really only gets recognition one day of the year – the shamrock.

It was originally chosen as Eire’s national emblem because of the legend that Saint Patrick used this plant to illustrate the Christian doctrine of the trinity.  The shamrock has also been considered by the Irish as a symbol of good luck since earliest times – a superstition that has persisted and spread to people of many nationalities.

Each year as we near St. Patrick’s Day, we see a proliferation of shamrocks being sold as ‘the real thing’, but in fact there is some dispute as to which variety is the authentic shamrock.  The most common plant being sold as a shamrock is Trifolium repens, a type of white clover.  According to my research, using many different sources, this particular plant is most widely accepted as the ‘real’ shamrock.  Many seed companies, in fact, sell the seed as the ‘true Irish shamrock’.  They are usually sold in 2½ or 4 inch pots around St. Patrick’s Day, and they make a fine little plant for a sunny windowsill.  They can also be planted outdoors almost anywhere, but the tiny yellow flowers are, quite honestly, not of great ornamental value.  But don’t forget that old legend of good luck!

A strong case can also be made for wood sorrel being the plant St. Patrick used.  Oxalis acetosella is native to the British Isles and during Elizabethan times, was a popular culinary herb.  Back in the 1600’s, herbalist Nicholas Culpepper also recommended it as a medicinal herb.  He suggested the plant would “quench thirst, strengthen weak stomachs and help repel any contagious sicknesses”.  In actual fact, the leaves contain oxalic acid which, if taken internally in large amounts, may cause diarrhea, kidney failure or hemorrhaging.  It does not sound very lucky to me!  On the other hand, this hardy perennial herb makes a novel ground cover with bright green tri-leaves and solitary white flowers that bloom from April through July.

Oxalis regnellii is a dandy houseplant with dozens of tiny white flowers that bloom persistently in spring and summer.  Not really hardy outdoors, in summer it makes a nice plant for a sunny patio. The secret to their care is to water them thoroughly, then let them dry out.

The newest oxalis to appear in the marketplace is a very unique purple leafed variety called. O. triangularis ‘Heartbreaker’.  It is an absolute beauty with its soft pink flowers contrasting nicely with its purple foliage.  ‘Heartbreaker’ is not very Irish, but it certainly is attractive.

One of the favourite shamrocks of most gardeners today is the ‘Iron Cross’ oxalis called O. deppi.  This hardy little variety is a real beauty in light shade or sunny garden areas, and its rosy pink flowers make quite a showing.  It may not be the real thing, but it is one of the best for our gardens.