Ensure a shamrock plant has plenty of bright light and is situated in an area with cool temperatures and plenty of fresh air. The Garden Helper advises that a shamrock plant's soil be kept moist during its active growing phase, but once it enters dormancy, the soil should be allowed to dry out in between watering. Shamrock plants grown indoors need two to three periods of dormancy annually to thrive.
Support the plant's dormancy needs by refraining from watering it when its leaves begin to brown. Allow the leaves to turn brown, removing them as they die off. Place the plant in a cool and dry location for two to three months, and water it only when the soil becomes very dry. After this rest period, resume regular watering and give the plant a feeding with plant food to encourage its growth.
While most shamrock plants require rest in two- to three-month increments, the purple leaf shamrock only requires one month of rest in between its active growing phases. Shamrocks require plenty of light to thrive; however, they don't do well in direct sunlight. Choose a location for an indoor shamrock that has indirect sun throughout much of the day while being sheltered from the hot late-afternoon sun.