Question:
My dumbcane has become tall, leggy, and unattractive. Can I rejuvenate it?Answer:
It’s possible to renew some old houseplants by layering. Layering is a procedure used to induce roots to form on a stem while it is still attached to the parent plant. Complete or partial girdling of the plant stem interrupts the downward translocation of carbohydrates and other compounds. The accumulation of these compounds promotes rooting at the point of injury.
The dumbcane (Dieffenbachia spp.) and other monocots can be layered by selecting a point 12 to 18 inches from the shoot tip. Make a sloping cut down toward the center of the stem. Immediately below the first cut, make an upward cut. The second cut should be approximately 1 inch below the first. The two cuts should meet in the center of the stem. Remove the cut portion of the stem. Dust a small amount of rooting hormone on the exposed surface. Place 1 or 2 handfuls of moist sphagnum moss around the exposed area. Wrap a piece of clear plastic around the sphagnum moss. Make sure none of the moss protrudes out the ends of the plastic wrap. Secure the plastic wrap above and below the sphagnum moss with twist ties. Roots should appear in the sphagnum moss in 6 to 8 weeks. When a good root system has developed, cut off the stem just below the bottom twist tie. Remove the twist ties and plastic and pot up the rooted stem in a well-drained potting soil.
After the layered stem has been removed, the parent plant can be discarded. However, it is also possible to save the original plant. Cut off the stem of the parent plant 2 to 3 inches above the soil surface. New growth will emerge from the stem and develop into a new plant.