Shamrock plants, known botanically as oxalis, are no-fuss houseplants that are treasured for their attractive triangular leaflets. Shamrocks are often sold in supermarkets and nurseries during the St. Patrick and Christmas holidays and make popular gifts. If you were given a lovely shamrock houseplant that has taken a turn for the worse, make sure you're meeting the plant's basic needs.
Provide your shamrock with appropriate sunlight and temperature conditions. Prevent or correct tall, lanky growth by positioning the shamrock where it has access to at least five hours of direct sunlight daily. Provide nighttime temperatures between 50 and 65 degrees Fahrenheit and daytime temperatures below 75.
Reduce watering frequency if the plant has yellow leaves. Allow the surface of your plant's growing medium to dry out a bit before watering; shamrocks grow best in soil that is kept slightly moist. If the problem persists, it may be an indication of root rot.
Clean and repot a shamrock plant with root rot to increase its chances of survival. Remove the shamrock from its container and examine the roots; affected roots will feel mushy. Rinse the roots under room temperature running water to remove the growing medium. Use a pair of sharp, sterile gardening scissors to trim affected roots from the plant; brush healthy roots with a fungicide product. Plant the shamrock in a clean container; use fresh growing medium comprised of equal parts potting soil, peat moss and perlite.
Avoid allowing the shamrock's growing medium to become too dry; this can cause the leaves of your plant to wilt. Increase the frequency of watering to revive wilted plants. Remember, shamrock plants prefer a growing medium that is kept moist, if only slightly.
Allow the shamrock to enter dormancy when its leaves die back at the beginning of summer; this is a normal resting period that will result in invigorated plant growth. Cut the foliage down to the growing medium and cease watering. Move the plant to a cool, dark location for two to three months. Return the shamrock to its original position and resume watering when new growth is observed.