Purple shamrocks, also known as Oxalis triangularis or false shamrock, are native to Brazil. They were first introduced to Europe in the 18th century and have since become a popular houseplant around the world. The name "shamrock" comes from the Irish word "seamróg," which means "little clover." While purple shamrocks are not true clovers, they share the characteristic three-lobed leaves and are considered a symbol of luck.
Habit: In the wild, purple shamrocks grow in moist, shaded areas such as forests and grasslands. They are often found growing under the shade of taller plants, which protect them from direct sunlight. A slender low growing tuberous perennial growing up to about 15 to 20 cm tall producing tufts of clover-like, dark purple leaves and slightly taller flower stalks of light pink trumpet-shaped smallish flowers. Note* Purple Shamrock should never be planted in the open garden in Zambia as it can quickly become a garden weed.
Temperature: Plants are happiest with temperatures between 15 to 25ᐤ C; temperatures below 10ᐤ C and higher than 30ᐤ C will start to cause the plants to go into dormancy where the leaves die back and the tubers will wait for suitable temperatures before starting back into growth.
Light Exposure: Plants will grow well in bright, indirect light to some exposure to weak direct light (either early morning or late afternoon sun). When placed in too dark of a location, leaves will lose the purple colour, reverting back to green to try to survive.
Watering: Purple Shamrock likes a moist growing medium but not soggy; water only when the top 1 or 2 cm of soil feels dry to the touch. Always check the soil moisture first but as a rule of thumb watering once or twice a week in the rainy season, once every two or three weeks in the cold dry season and twice a week in the hot dry season. If plants dry out completely, it will not die but instead goes dormant and starting watering again will bring the plant back into growth.
Fertilising: Give plants a well balanced fertiliser once a month during the hot dry season and rainy season but not during the cold dry season when plants are resting (semi-dormant).
Pruning/Repotting: Remove drying or dead leaves and old flower stalks as needed. Since the plants are small, they do not need to be repotted for four to five years; alternatively, plants can easily be divided to make more pots of.They prefer slightly acidic soil with a pH between 5.5 and 6.5.
Pests/Diseases: While purple shamrocks are relatively easy to care for, they are susceptible to some common houseplant pests, such as spider mites and mealybugs. If you notice any signs of infestation, such as webs or sticky residue, isolate your plant and treat it with an appropriate insecticide or soap spray.
By providing them with the right environment and care, you can enjoy their vibrant foliage and symbol of luck for years to come.