A house plant guide to Dumb cane plant care
The Dumb Cane plant is a strong little species that will thrive in any light conditions other than direct sunlight. This popular foliage plant is often called dumb cane because the plant’s sap contains calcium oxalate crystals that are potent irritants of human and animal mucous membranes, and chewing the leaves causes the tongue and throat to swell, making speech impossible (and suffocation a possibility). The sap is poisonous to cats, too, so they should not be allowed to play with the leaves.
As for the “cane” part of the name, older dieffenbachias typically grew quite tall until they became tufts of leaves atop a canelike stalk. Some still do, though modern hybrids are more compact and bushy than were their forebears. Many grow to only 12 in/30 cm tall. Numerous hybrids are available that feature different variegation patterns in the leaves, and you may occasionally find all-green dieffenbachias as well. When breeders evaluate new dieffenbachias, they look for a low incidence of leaf burn due to fluctuations in fertilizer and light levels — the most common problem with the dumb cane plants.
As for the “cane” part of the name, older dieffenbachias typically grew quite tall until they became tufts of leaves atop a canelike stalk
Common name: Dumb cane or Leopard Lily
Botanical name: Dieffenbachia, Dieffenbachia hybrids
Origin: Central and South American rain forests
Light: Moderate filtered light. Turn plant often to encourage even growth.
Temperature: Average to warm room temperatures (65–80°F/18–27°C).
Fertilizer: In spring and summer, high-nitrogen foliage plant food or balanced plant food every 2 weeks. In fall and winter, feed monthly.
Water: Keep soil lightly moist, never waterlogged, with moderate humidity. Plant adapts easily to most homes and offices.
Soil: Any good potting soil.
Repotting: Every other spring.
Longevity: 3 to 15 years; indefinitely when propagated from rooted cuttings.
Selections: Choose varieties based on your personal preferences, because they’re all good.
Display tips: Dieffenbachias work well in formal rooms when grown in brass or ceramic containers. In mixed containers, they combine well with arrowhead vine, pothos, and prayer plant.
Dumb cane plant propagation guide. How to propagate dumb cane plant
When a dieffenbachia grows too tall, use a sharp knife to lop off the top of the plant so that a 6 in/15 cm-tall trunk remains. When pups emerge from the lower stem, cut them away and plant them in small pots. In addition, you may have luck trimming the excised top to about 6 in/15 cm long, while removing all but the three or four topmost leaves. Set the groomed tip in a jar of water to root for 3 weeks, and then transplant to a new pot.
Dumb cane plant disease and troubleshooting
CAUSE: Too little water.
REMEDY: Water plants lightly yet frequently so that the soil never dries out completely.
Brown tips on leaves.
CAUSE: Uneven watering.
REMEDY: Provide water frequently, but never force the roots to sit in water. Learn to judge moisture level in container by tipping it to assess its weight as well as by checking for moisture in the top inch of soil.
Leaves droop and fall without yellowing first.
CAUSE: Plant is being chilled.
REMEDY: Move plant to a warmer place where temperatures will stay above 60°F/16°C.
New growth is lopsided or uneven.
CAUSE: Plant is stretching toward light.
REMEDY: Turn the plant a quarter turn every 3 days. If the plant still appears lanky, increase light level by moving it to a brighter spot.
Little or no new growth.
CAUSE: Insufficient light or not enough fertilizer.
REMEDY: Provide supplemental light or move to a brighter location; feed plant every 2 weeks with a high-nitrogen foliage plant food.
Leaf edges turn brown and curl.
CAUSE: Too much fertilizer.
REMEDY: Flush soil with clean water to wash away any accumulated fertilizer and salts. After 2 weeks, resume feeding with a dilute solution of water-soluble houseplant food.
Lowest leaves turn yellow and drop.
CAUSE: This is the normal growth pattern of this plant.
REMEDY: Snip off failing leaves during regular grooming.
White, cottony masses on stems and leaf undersides.
REMEDY: Clean off with swabs dipped in alcohol. Repeat every 3 days until the mealybugs are gone.
Leaves appear pale and bleached, with webby material on leaf undersides.
CAUSE: Spider mites.
REMEDY: Isolate plant and treat the problem immediately. See page 274 for detailed information about this pest.