Dumbcane (Dieffenbachia)

Calthea for sale at a garden center

Chinese Evergreen (Aglaonema), Dumbcane (Dieffenbachia), and Calthea (Calthea spp.) are three similar looking  tropical house plants (USDA hardiness zones 8 through 11). Likely, you have seen these easy to grow foliage plants inside restaurants, shopping malls, offices, and at the public library.

They grow in medium to low light areas of the home or work place where many flowering plants will not thrive. They dislike room temperatures below 55 °F and a dry atmosphere. Browning leaf edges may be a symptom that room air is too dry. Turn plants every few weeks for furnish adequate light to all sides of the plant.

Spring-summer-fall fertilizing should be every 2 weeks with a water soluble “house plant fertilizer” at one-half package directions. Winter feeding is usually unnecessary. Irrigate with room temperature non-fluoridated water to avoid burning the foliage.

Plants may be moved outdoors in summer and placed under a large shade tree to receive filtered or indirect light only.

Always water plants thoroughly and do not leave them sitting in standing water for long periods. Plants should be repotted annually, usually in early fall or in late winter. Snip off older bottom leaves that have withered and died.

Diseases rarely bother all three foliage plants. Occasional pests are aphids, mealy bugs, spider mites and scales that may curl, speckle and bronze leaves. Inspect the leaf underside for webbing and spray with insecticidal soap or neem oil. Respray every one to two weeks until pest has been managed.

Chinese evergreen (Aglaonema) has a decorative patterned foliage and available in many varieties.

Dumbcane (Dieffenbachia spp.) reach heights of 4 to 6 feet; related to Aglaonema, Spathiphyllum and Philodendron.

Calthea (Calthea spp.) available in many varieties with colorful foliage and flowers in plant family Maranthaceae.

Caution: Foliage of Chinese evergreen and dumbcane are toxic and should not be ingested. If chewed or eaten, it can cause temporary swelling of the tongue and throat, leading to a temporary loss of speech and sometimes may result in suffocation. Keep plants away from children or pets. Calthea leaves are not toxic.