St Patrick's Day
Sunday, March 4, 2007
The plants sold prior to 17 March as "Irish Shamrock" are likely to be Oxalis. Since there are several hundred species, identifying which is something of a conundrum. Alfred Byrd Graf, one of the greatest experts on indoor ornamentals, has written that Oxalis oregana, a wood sorrel native from California to Washington was "sometimes sold as 'Irish Shamrock'." Hedging his bet, Graf also labelled O. deppel from southern Mexico as 'Lucky Clover.'
As far as Messrs. Roger Hyam and Richard Pankhurst from the Edinburgh Botanical Garden are concerned, Oxalis deppel is more correctly O. tetraphylla -- 'Lucky Clover' or 'Good Luck Plant,' take your choice. However, they dismiss O. corniculata as "a persistent weed of greenhouses." Strangely that is the wood sorrel that some people believe is the true shamrock of St. Patrick, the national emblem of Ireland. According to legend, St. Patrick used the triple leaf of the wood sorrel leaf to explain the Holy Trinity to his heathen Hibernian audience when trying to convert them to Christianity. At least so say Wee Yeow Chin and Hsuan Keng, experts in Chinese pharmaceuticals in which O. corniculata apparently finds favour as a cooling agent, to expel intestinal worms, increase the flow of urine and control bleeding.
Truth to be told, what exactly shamrock botanically is would leave even the blessed St. Patrick himself puzzled. Surveyed, most inhabitants of the Emerald Isle identified it with four-leaved clover. The Irish Embassy in Ottawa maintains a diplomatic silence on the subject.
No confirmation either that a Canadian-Irish scientist has managed to genetically combine shamrock with poison ivy, thus achieving a rash of good luck.
March has come to mean pruning month in some quarters. The 'Death of a Thousand Cuts' is more like it for many an innocent shrub. A general rule is to prune summer-flowering shrubs this month but leave those that bloom in spring until after they finish flowering. Evergreens are left until late spring.
So what was George Bernard Shaw, having just celebrated his 94th birthday on 26 July 1950 doing out in his garden pruning shrubs a short time later? The pre-eminent playwright and supporter of socialism fell, fracturing his thighbone and leading to his demise, which was hastened by a necessary operation for kidney stones.
A lesson though for would-be amateur tree loppers: If you cannot reach it from the ground without a ladder, call in a tree surgeon. Let them fall out of their patient. Apple and other fruit trees are pruned about March and many other trees also. All except some of the most commonly grown that is -- maples, birches, poplars and willows. These tend to spill sap in copious quantities during spring so are left until later.
A basic rule of pruning: in general, the more you cut off deciduous shrubs, the more growth is created. Remember also that the best foliage, flowers and fruit occur on younger wood. Remove older wood and encourage new growth. Watch as well for branches crossing each other -- they will rub and damage each other as well as cause overcrowding.
Indoors, if you find the white salt stains on clay pots unsightly, wipe the pots down with a rag soaked in vinegar. Plant parts coming in contact with such salt-impregnated pot rims may suffer damage.
Meanwhile dusting with cinnamon powder can discourage moulds or fungus growing on the soil surface. Some claim that watering coffee grounds into the soil fights off fungus gnats although personally we have found this seems a source of such moulds and fungus.
Start summer-blooming bulbs such as tuberous begonia, canna and dahlia in 6-inch pots in March so they will already be in bloom when planting out time arrives. Tuberous begonias, incidentally, are one of the few plants that will grow under black walnut trees, which release a natural herbicide into their surrounds.
While you are at it, sow tomato, pepper, eggplant and basil seed inside this month. Variety selection is far superior in seed catalogues than the limited selection offered at most retail outlets.
Perhaps though taking a break for St. Patrick's Day is just not your thing. Coincidentally, 17 March was also celebrated in Rome as the feast day of the Liber. An ancient Italian deity of the vine, he later became a symbol of fertility. St. Augustine was aghast to observe a six-foot-high wooden phallus drawn on a wagon through city streets as part of the Liberalia celebrations. A virgin selected by the priests later crowned the erection with a wreath -- something not seen even in Toronto. Sic transit gloria mundi.
Wes Porter is a horticultural consultant and writer based in Toronto. He has over 40 years of experience in both temperate and tropical horticulture from three continents.