Dieffenbachia maculata, commonly called Spotted dumbcane, is a popular home or office plant that is readily found in local garden centers in a variety of leaf patterns. With a spread of 2 to 3 feet and heights of as much as 8 feet, it makes its presence known in most any room you place it.
Because it is a USDA Zone 10 to 11-rated plant (native to Central and South America), it must remain as an indoor plant in Routt County. In fact, the only place in the U.S. that it can be grown outdoors is the very southern tip of Florida and in the tropical paradise of Hawaii. It will die in temperatures that drop below 40 degrees, which can happen here every night of the year.
Its common name comes from a property of the plant that is toxic if ingested. The leaves and stem contain a poison that can paralyze the vocal cords if ingested, so this is perhaps not a good plant to have around young children or pets that might have a tendency to put things in their mouths. It causes a painful irritation of the mouth and tongue that can take several days to dissipate.
Because the large (as much as 1 foot long) leaves are variegated, this plant does best when placed in an area of the room that is bright but not in direct sunlight. And because the leaves are so large, humidity might be necessary to keep them from drying out on you. A container filled with stones and water placed near the plant can help with this.
Dieffenbachia prefers moderately moist soil that is allowed to dry between waterings, and it can use regular fertilizing. A mix of 20-20-20 every four to six weeks during the growing season will keep the plant healthy and growing. If you wish to limit its growth so it will maintain a desirable shape, cut back on fertilization. If the leaves turn yellow, it could be sign of nutrient deficiency or lack of water. And if lower leaves drop off, it could be a sign of overwatering as well as a sign of a change in temperature.
As the plant grows, some leaves may curl up and fall off the plant. This is a normal growth pattern as it makes room for new leaves to sprout off the stem.
You can propagate this plant by removing new shoots and placing them in a growing medium such as peat, perlite or vermiculite. You also can take 2-inch sections of bare stems and propagate them in the growing medium. Be sure to take care when trimming this plant or taking cuttings as the toxins from the leaves could transfer from your hands to your eyes or mouth, causing a painful reaction.
Dieffenbachia can be affected by mites, mealy-bugs and scale, most of which can be remedied by wiping the leaves down with rubbing alcohol on a cotton ball or spraying with an insecticidal soap. Some of these remedies can harm a delicate plant, so test one leaf first before treating the whole plant.
If you want to add some greenery to your home or office, you can’t go wrong with this plant.
Deb Babcock is a volunteer Master Gardener through the CSU Extension Routt County. Call 970-879-0825 or email CSUMGProgram@co.routt.co.us with questions.