PPDL Picture of the Week for
March 18, 2013

Caring for Shamrocks Year Round

Rosie Lerner, Extension Consumer Horticulturist, Horticulture & Landscape Architecture, Purdue University

Although sometimes referred to as clover, the shamrock is not a “true” clover, but more typically one of several species of Oxalis. The Oxalis selections commonly sold as shamrocks are grown more for foliage than their flowers. Both green and purple foliage are popular and some have quite striking variegated patterns. The shamrock's dainty flowers vary from white to pink to lavender to yellow, depending on the cultivar. Their flowers close at night and during cloudy weather, making it an interesting plant for youngsters of all ages.

The shamrock's low, trailing habit makes them a good specimen for a hanging basket or for a table top-planter. The roots like to stay close to the soil surface so they should not be planted too deeply. Water the plants when the top of the soil feels a little bit dry, but be careful not to let the pot get too dry since the roots are shallow. Use a fertilizer for blooming houseplants according to label directions.

Shamrocks grow well in average house temperatures and especially prefer cooler temperatures at night. Bright, indirect sunlight is acceptable, but a few hours of direct sunlight will help encourage blooming. A sunny east or west-facing window is ideal.

After blooming, it's a good idea to allow plants to rest by allowing the soil to dry a bit more than usual and discontinue fertilizing. Resume normal plant care in about 2 months.

Click image to enlarge

Oxalis 'Charmed Wine'

Oxalis 'Charmed Jade'

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service