PINK, NOT BLUE

Ask any horticulturist or any gardener to describe the plant known as Periwinkle and you will be told that it is a wiry-stemmed, sometimes evergreen, sub-shrub with sky-blue flowers; known botanically as Vinca minor. The flowers of Periwinkle are famously blue but you can dare to be different and seek the wine-red or white. A dissenter might suggest Vinca major; a trailing type much used in hanging baskets and containers. This form with variegated green and white foliage is tender and used only as an annual.

    The pamphlet ‘ Information for Families-Plant Safety ‘ that the Poison Information Centre co-publish with Sick Kids’ Hospital does not provide botanical names. Families have to do a lot of guessing. In fact it is very short of information; they tell you nothing. In their list of ‘plants known to be poisonous to humans’ they make an exception for Periwinkle, (Vinca). The one and only time that you are given the plants’ botanical name, and they get it precisely wrong.

     If there is a Periwinkle that might be poisonous (by their standards, not by mine) it would be Madagascar Periwinkle. Admittedly, it was once Vinca rosea, so-named by the great Linnaeus but changed to Catharanthus roseus by the English botanist George Don. This name change is not recent. Don died in 1846.

     Medical staff at the hospital will know the therapeutic value of Madagascar or Rosy Periwinkle. Two potent chemicals derived from this plant are vincristine and vinblastine which became the drugs of choice in the treatment of childhood leukemia and Hodgkin’s disease.

     The concentration of active ingredients in Catharanthus is so low that that it takes more than 250 kilograms of leaves to make one 500mg therapeutic dose. Rather more than the few plants in your window box.

     Only an ill-informed smart Alec or Alicia would interpret the medicinal use of Rosy Periwinkle as cause for a public alarm and to call the plant poisonous. It is a joke. Our world-famous Hospital for Sick Children is poorly served by lending their name to this shabby list.

     Garden Centres now offer so many plant choices that Rosy Vinca has lost its’ once prominent place in our summer gardens. Putting aside the plants’ value as a pharmaceutical (It is now grown world-wide for that purpose) to look at the plants qualities as an ornamental: Madagascar Periwinkle shows its’ Indian Ocean origins by revelling in heat and humidity. The open five-lobed flowers can be rosy pink or white, usually with a red eye. Grown in the sunniest spot in the garden it has the look of a small roundish 60cm shrub and will produce flower clusters all summer. The attractive leaves are dark green with a noticeable mid-vein that combines as an attractive package.

I intend to help this fine plant overcome the unwarranted slurs it has suffered at the hands of the uninformed. I cannot recommend Rosy Vinca too highly.

     This is an annual to die for, if you will excuse the expression.