The label “prayer plant” covers several species of foliage houseplants, including Maranta and Calathea. The plants share a trait of raising their leaves at night as though in prayer. During the day, the leaves extend outward. Prayer plants perform nicely in terrariums as well as pots.
Each stem terminates in a colourful leaf. The leaves fold inward as they are lifted in the evening on some varieties. Other varieties simply bunch the leaves more closely together in a vertical column. If the leaves uncurl each morning, the plant may be demonstrating the behaviour which inspired the nickname.
Prayer plants require high humidity and moist soil without standing in water, according to horticulturist Ron Smith of the North Dakota State University Extension Service. A moisture deficit can trigger changes in leaf margins, including browning and spotting. Provide humidity by placing the plant near other plants. Gardeners can create a more humid environment for a lone plant by placing it in a shallow pan on a layer of stones. Fill the pan with water up to the top of the stones but not so far as to enter the bottom of the pot.
Prayer plants prefer temperate ranges, 20 to 23.9 degrees Celsius. In winter, plants can tolerate temperatures in the high 50s for short periods. Exposure to temperature extremes for prolonged periods can damage foliage and cause spindly development.
Indirect bright light provides the optimum environment for prayer plants. Too much direct light stresses the plant and can result in damage to the leaves. Seasonal changes in the length of days may require a repositioning of the plant to ensure adequate light or prevent overexposure.
Regular feedings benefit prayer plants. A light feeding twice a month with a 15-30-15 fertiliser will provide the minerals essential for the plant to thrive. Avoid over-fertilising which can damage the plant.
Check the foliage for evidence of insect infestation. Some pests can cause damage to plants resulting in leaf curling. Identify any insects present and use an appropriate legal treatment to clear the plant of the infestation. Separate the infested plant from other plants until the problem has been resolved; this will help to keep the pests from spreading.
Apply a cosmetic remedy for damaged foliage by removing any severely damaged leaves and trimming any minor damage. Use clean, sharp scissors. Discard the damaged foliage.