Persian shields like to be kept in consistently moist soil. They are not drought-tolerant, so you will need to keep on top of watering the plant to make sure it doesn’t dry out. When kept as a houseplant, you can expect to water your Persian shield at least twice a week, though always dip your finger into the soil to see if it is ready to be watered. Only water the plant once the top layer of soil has dried out. Otherwise, you risk drowning your plant and causing root rot.
Pay extra attention to your plant’s watering needs in the winter, when indoor heating systems may cause the soil to dry out faster than usual. For outdoor plants, moist soil should also be maintained. Water regularly throughout summer, especially in times when rainfall is lacking.
When grown outdoors, the Persian shield can tolerate full sun, though it prefers partial shade. In its natural habitat, it would grow under the partial shade of overhead trees, so it’s best to try to replicate this as best you can in your own garden. Ideally, recreate this environment by planting the Persian shield under the protection of other trees, which can provide dappled shade.
If you must plant it in a sunny spot, ensure it gets afternoon shade to protect it during the hottest time of the day. If the plant gets too much sun, it will struggle to produce the vibrant purple foliage it is loved for.
Persian shield is hardy from USDA growing zones 9 through 12, where it will grow as a perennial. It can be grown in zones 7 and 8, though it will grow as an annual. In these cooler climates, the plant will die back in the winter, but as long as the root system doesn’t freeze and die, then it will bounce back to life in the spring.
To help prevent the roots from freezing, you can insulate the soil by mulching it over before the first frost or use a horticultural blanket to protect the plant from cold temperatures. Alternatively, if the plant is grown outdoors in a container, you could bring it indoors during cooler months to overwinter it.
Persian shields have a tendency to grow leggy and spindly, which can look unattractive. To prevent this from happening, pinch back the leaves in early spring to encourage a fuller and more bushy growth. If your plant blooms, you may wish to remove the flowers as they appear. Most people find the flowers uninteresting compared with the colorful foliage, and pinching off the flowers will ensure the plant’s energy focuses on leave production rather than blooming.