Botanical name: Dieffenbachia spp
Dumb Cane (Dieffenbachia) is a popular plant with large and highly decorative leaves, easy to grow and a good air cleaner. The stems are straight and may grow to a height of 5 ft under room conditions.
The leaves are simple and alternate containing white spots and flecks which make it an attractive houseplant. The lower leaves in Dumb Cane will normally fall to give the plant a False Palm effect.
The common name, "Dumb Cane", is derived from the unpleasant effect of its poisonous sap on the mouth and throat.
Dieffenbachia is poisonous to both humans and pets if ingested. Always wash hands thoroughly after handling.
Dieffenbachia is native to the New World Tropics from Mexico and the West Indies south to Argentina.
There are many varieties of Dumb Cane available with varied leaf patterns and not all are easy to grow.
The Dieffenbachia amoena and Dieffenbachia picta varieties are fairly tolerant and easy to grow.
Dieffenbachia amoena has dark-green foliage with white bars, the stems can reach a height of 5 ft and the leaves are 1.5 ft long at maturity.
Dieffenbachia picta is the most popular, bearing oval leaves with ivory white blotches or markings.
Other varieties include Dieffenbachia oerstedii which bears all-green leaves with a prominent white mid-rib, the yellow-green Dieffenbachia bausei and the giant-leaved Dieffenbachia bowmannii among many others.
According to the NASA Clean Air Study, Dumb cane was found to remove common VOCs like formaldehyde, toulene and xylene from indoor air.
If you are looking to add this plant to your collection, various Dumb Canes are available online at Etsy. Buy Dumb Cane (Dieffenbachia spp) online from Etsy.
Photo Credit: Crocus
Dumb Cane (Dieffenbachia) thrives in bright indirect light away from direct sunshine, warm and humid conditions and moderately moist, fertile, well-drained soils coupled with fortnightly feeding during the growing season.
Dieffenbachia requires pruning to keep it neat, to minimize pest and disease infestations and to rejuvenate growth. Repotting is done annually at the beginning of the growing season. Keep reading for the best growing conditions and how to provide them.
Dumb Cane grows best in bright indirect light away from direct sunshine. Direct sunlight will lead to leaf scorch while too bright light causes loss of leaf color.
Rotate the pot regularly to ensure that the plant gets light on all sides, which prevents it from bending towards the light source.
Dieffenbachia can also grow under a grow light where natural light is not sufficient.
Water Dumb Cane liberally during the growing season and allow the top 1-2 in. of soil to dry out between waterings to keep the soil consistently moist.
Reduce watering in the cold season to maintain the soil slightly moist but do not let the soil dry out completely.
Make sure that the pot has a drainage hole to prevent the soil from getting soggy as it can lead to stem-rot and eventual death of the plant.
Average to above average warmth with a minimum of 150C is ideal for Dumb Cane. Keep it away from cold draughts as it is very sensitive to cold temperatures which may lead to yellowing and wilting of the lower leaves.
Average room humidity is ideal for Dumb Cane. When the temperatures are very high causing the air to become too dry, the plant with respond with brown leaf tips.
To increase humidity to prevent brown leaf tips, set the pot on a wet pebble tray or use a cool mist humidifier. Read more on how to raise humidity for houseplants.
Regularly clean the leaves by damp-wiping with a soft cloth to get rid of dust and discourage pest infestations.
Feed Dumb Cane every 2-3 weeks during the growing period with a balanced, water-soluble fertilizer to encourage foliage development.
Withhold feeding during the cold season as growth is minimal and feeding at this time can lead to fertilizer burn.
Repot Dumb Cane annually at the beginning of the growing season. Use a pot 1-2 sizes larger and one that has drainage holes. Never allow the roots to sit in soggy soil as it can lead to stem-rot and death of the plant.
Pruning Dumb Cane involves removal of dead and yellow leaves to maintain the plant neat and tidy as well as discourage pests and diseases.
With age, Dieffenbachia becomes leggy and unattractive. Cut off the cane, leaving a 4 inch stump. Use the crown for propagation. The stump will resprout to produce a new plant.
Dumb Cane (Dieffenbachia) can be propagated at the beginning of the growing season from stem cuttings, from offshoots and from the top crown of leaves.
Take 2-3 in. long stem cuttings from a healthy Dumb Cane. Ensure each cutting has at least 2-3 leaf nodes as this is where new growth will come from.
Dip the lower cut-end of the cutting in a rooting hormone and insert it in moist, free-draining rooting soil.
Place the set up in a warm, well-lit place away from direct sunlight. Roots will develop in about 3-6 weeks.
Once there is new growth, the rooted Dumb Cane cuttings can be transplanted into individual pots.
Some varieties of Dumb Cane produce daughter plants (pups or offshoots) at the base.
Seperate the pups from the mother, with some roots when at least 10 in. tall and pot them in individual pots.
Place the pots in a warm, brightly-lit place and maintain the soil moist through out until new growth emerges.
Allow the new Dumb Cane to be well established before transplanting.
Remove the top crown of leaves of Dumb Cane bearing about 3 in. of stem.
Apply a rooting hormone on the stem of the crown of leaves and insert it in moist, free-draining, rooting soil.
Place the set up in a warm, well-lit place and maintain the soil moist until new growth emerges.
Allow the new Dumb Cane to be well established before transplanting after which routine care begin.
Photo Credit: Plant Circle
Dumb Cane (Dieffenbachia) problems indoors include yellowing, wilting, rotting, brown leaf tips, leaf drop, pests and diseases among others. Keep reading for more details on these problems and how to solve them.
Too low temperature below 100C or cold draughts are the causes of yellow and wilted leaves in Dumb Cane.
Maintain average to above average temperature for the plant and keep it away from cold draughts like windy doors and windows, air conditioning units and others.
Soft and discolored stem base in Dumb Cane is an indication of stem-rot disease, which is encouraged by soggy soil and low temperatures.
Cut out diseased parts and treat the palnt with a fungicide. If badly damaged, discard it as it is too far gone.
Avoid soggy soil in the future by ensuring that the pot has a drainage hole and the soil is free-draining.
Ensure also to maintain average to above average room temperature for the Dumb Cane and keep it away from cold draughts.
Naturally, the lower leaves fall to give Dumb Cane a False Palm effect. If the young leaves are falling there are three possible causes of this.
One possible cause of leaf drop in young Dumb Cane is cold temperature. Maintain an average to above average temperatures with a minimum of 100C and keep the plant away from cold drafts.
The second possible cause of leaf fall in young Dumb Cane is dry air (low humidity) especially where the room temperatures are very high.
To elevate humidity, set the pot on a wet pebble tray. Check out these techniques on how to raise the air humidity for houseplants.
The third possible cause of leaf drop in a young Dumb Cane is cold draughts. Keep it away from cold draughts to avoid sudden drop in temperature which causes the leaf fall.
There are two possible causes of brown leaf tips and edges in Dumb Cane. One possible cause is that the soil has been allowed to dry out.
Maintain the soil moist at all times during the growing season and slightly moist in the cold season but never allow the soil to dry out completely.
The second possible cause of brown leaf tips and edges in Dumb Cane is the air is too dry (low humidity).
To raise humidity, set the pot on a wet pebble tray or use a cool mist humidifier.
The cause of yellow lower leaves in Dumb Cane is underwatering. Ensure the soil is consistently moist during the growing season and slightly moist in the cold season but never allow the soil to dry out completely.
Exposing Dumb cane to direct sunlight or excessive brightness will lead to loss of leaf color. Move the plant to a more shaded spot or shield it from direct sunlight by installing a light curtain.
Too little light is the cause of small new leaves and leggy growth in Dumb Cane. Position the plant in a brighter spot and ensure it is receiving bright, indirect light away from direct sunlight.
Common pests in Dumb Cane are Scale Insects and Spider Mites. Isolate the affected plant to prevent spread to other plants and treat it with a horticultural oil as per the manufacturer's recommendations.
Dumb Cane (Dieffenbachia spp) is toxic to both humans and pets as outlined by ASPCA.
If the leaves are chewed or ingested, they may cause temporary swelling of the tongue and the throat which may lead to a temporary loss of speech and hence the common name dumb cane. In severe cases suffocation may occur.