How to Take Care of Purple Heart Plants Also known as purple queen, purple heart (Setcreasea pallida) is a striking plant with fuzzy, purple, lance-shaped leaves that reach lengths of 7 inches. The stems grow straight up and then lean over, creating a cascading effect. Bright purple flowers appear at the end of the stems in summer and autumn. Purple heart works well as a ground cover or in a patio container or hanging basket. Purple heart is suitable for planting in U.S. Department of Agriculture growing zones 9 through 11. In cooler climates, it is often grown indoors. Outdoors 1 Water young purple hearts regularly, keeping the soil evenly moist until the plants are established and display new growth. Thereafter, water the plants only during periods of dry weather. Water generously to saturate the root zone as shallow watering creates shallow, weak roots. Don't water again until the soil is dry. 2 Pinch off the tips of stems to to create a bushier plant. Repeat whenever the plants begin to look leggy or spindly. After flowering, cut the stems back to about half their height. Pruning the plants creates healthy, vibrant plants. 3 Fertilize purple heart once every month while the plants are actively growing. Apply a general-purpose dry or liquid fertilizer according to the guidelines provided on the label. Always water immediately after applying fertilizer. Decrease feeding in the winter months, then resume when new growth appears in spring. Indoors 1 Plant purple heart in a container filled with commercial potting soil. Be sure the container has a drainage hole to prevent soggy soil and root rot. Use a good quality, lightweight, commercial potting mix consisting of peat moss, perlite or compost. 2 Place the container in full sun or partial shade. Bright sunlight brings out the intense purple of the leaves. 3 Fertilize the plant monthly, using a general-purpose liquid fertilizer for indoor plants. Apply the fertilizer to damp soil at the rate recommended on the label. Applying fertilizer to dry soil may burn the roots. Withhold fertilizer during the winter months. 4 Pinch the growing tips of the plant to create a bushy, compact plant. Repeat as needed to maintain the desired size and shape. 5 Keep purple heart in normal room temperatures of approximately 60 to 70 degrees F during the day, and about 50 to 55 degrees F at night.