Jennifer Schultz Nelson
Extension Educator, Horticulture
In the spirit of St. Patrick's Day, perhaps you bought an "Irish Shamrock" at your local garden center or maybe even the grocery store. These plants are actually part of the Oxalis genus, and are a very unique houseplant to have in your home.
I have seen Oxalis in the store many times, and purchased one for the first time this year. The first night, I thought I had killed it. There it sat on my table, leaves not exactly wilted, but folded downward. I chalked it up to the shock of the trip home, and hoped for the best. In the morning, it looked fine, and I thought nothing of it. Then in the evening it the leaves looked folded again. Was I doing something wrong? Was it too cold, too dark, somehow not the right environment in my home? A little research revealed that this nighttime leaf folding is normal for Oxalis.
I also learned that Oxalis grows from small bulbs or tuberous roots. It thrives in bright light, cool temperatures, and moist soil. Fertilizing with standard houseplant fertilizer during active growth is recommended. Unlike most houseplants, it actually prefers to be crowded in a too-small pot.
Most Oxalis will produce tiny white, pink, or red flowers held above the foliage. Do not be surprised if despite your best efforts, your Oxalis' leaves begin to yellow and die. Many Oxalis need a period of rest or dormancy, as do most bulbs. It is not unusual for Oxalis to go through this dormancy period two or even three times per year. As the leaves yellow and die, you should cease watering. Place the plant in a cool, dark place, such as a basement, and resume watering only when new growth is observed.
Oxalis foliage is usually green, though some varieties have deep red foliage. Irish or not, Oxalis are a surprisingly easy and interesting houseplant to grow!