Climate and Soil
Plant Stromanthe in shade to filtered sun for best results. The lowest winter temperature this tropical plant should endure is 59 degrees Fahrenheit. Stromanthe is classified for USDA Hardiness Zones 10 and 11. To find your hardiness zone, check the U.S. National Arboretum website, www.usna.usda.gov. Plant Stromanthe in sandy loam or clay loam with a pH range of 5.5 to 6.5.
Follow the instructions on the plant's label to determine proper depth and spacing. Although some perennials can be planted in the fall, plant Stromanthe in the spring so it can establish itself in warmer temperatures before its first winter. Water the plant and let it drain before gently removing it from its container. Loosen the root ball a bit, especially if it appears to be root bound. Place the plant in the hole and fill in soil around it, patting the top layer firmly when finished. Water thoroughly. Protect the plant from direct sun until it is established.
Thin the Stromanthe occasionally to keep it from spreading too far and taking over other areas. Thinning also increases air circulation around the leaves to help prevent diseases like mildew. Over time, the root mass may become too dense, leading to a less-vigorous plant. To avoid this problem, occasionally separate a stand into smaller chunks and replant the extra part elsewhere.
Keep the soil moist. Stromanthe grows best in moist soil that's not allowed to dry out between waterings. It also may benefit from being sprayed with water about once a week. Typically about 1 inch of water per week is sufficient, but Stromanthe requires less watering during the winter, so reduce water between late November and early March.