Purple Oxalis Oxalis triangularis, is a plant that is definitely on my must-have list. It’s a deep, velvety purple, it looks great on its own or mixed with other plants, it’s versatile, and it’s pretty hard to kill. Sometimes called a Purple Shamrock, Oxalis’ deeply coloured leaves resemble overgrown clover leaves. They also display an intriguing quality called photonasty. A nastic plant is one that moves in response to certain stimulus. In the case of the oxalis, it moves in response to light, opening in the day and folding its leaves downward at night. It’s the kind of phenomenon kids love, so makes a great plant if you want to get your children interested in plant-life and gardening.
One of the best uses I’ve seen for Oxalis is planted at the base of a twining plant, like a potted passionflower. They fill out the bare spot at the base, and adds rich colour and foliage interest. Oxalis makes a neat mound in a pot, and will take part sun. I’ve also potted it with an orange geranium, and the purple and orange make a great contrast. It looks great with any lemon-lime foliage as well.
Oxalis do have flowers—delicate, white blooms—but they really are grown for their magnificent purple leaves. The plants grow from small bulbs, and they do multiply, so you can repot and spread them around quite successfully. Oxalis isn’t hardy in the ground in Canada, but as a potted plant it can summer outdoors and winter inside. It will go dormant for a few weeks, and then start new growth in the spring. It’s a real keeper. Once you bring home one pot of oxalis, you’ll never be without it.