Dieffenbachia (Dumb Cane): Toxic to Pets and People

ASPCA Animal Poison Control lists Dieffenbachia (Dieffenbachia spp.) as toxic to cats and dogs. The toxic principle is Insoluble calcium oxalates, proteolytic enzyme. Signs reported: Oral irritation, intense burning and irritation of mouth, tongue and lips, excessive drooling, vomiting, difficulty swallowing.

If a pet may have eaten a plant, contact a veterinarian, ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661. Note what was eaten, how much and when, and bring a photo or a piece of the plant. Do not induce vomiting or give home remedies unless a professional tells you to.

• Aloe Vera
• Azalea
• Chrysanthemum
• Cyclamen

Toxicity lists are by species, and many houseplants look alike. Photograph the whole plant, a leaf close-up and any flower in even light; the app reads the species first, then you can check it here. If the species is uncertain, act as if it were toxic.

The risk comes from the sap, which reaches skin and eyes when leaves or stems are cut, broken or chewed. Dieffenbachia tissue contains raphides, needle-shaped calcium oxalate crystals; Missouri Poison Center explains that these pierce tissue, together with enzymes that amplify the irritation, and that chewing is what releases the sap. The reported effects are skin irritation and rash, and eye pain and irritation.

Poison Control (poison.org) gives the first aid:

• Skin: wash the area with soap and water for 15 minutes.
• Eyes: irrigate with water for at least 15 minutes.
• Mouth: rinse, spit out plant material, and call. Call 911 for severe mouth swelling, heavy drooling, trouble swallowing or trouble breathing.

In the United States, call Poison Control on 1-800-222-1222 for any exposure in a person. Wear gloves when you prune, repot or take cuttings, and wash your hands before touching your face.

The common name describes the poisoning. Wikipedia notes that the English names refer to the effect of the raphides, which can cause a temporary inability to speak, and Poison Control lists loss of speech alongside swelling and drooling if the plant is swallowed.

The genus was named by Heinrich Wilhelm Schott, director of the botanical gardens in Vienna, after his head gardener Joseph Dieffenbach (1790-1863). The plants are native from Mexico and the West Indies south to Argentina, and Wikipedia counts 60 accepted species as of January 2026.

Wikipedia also describes stories that dieffenbachia is a deadly poison as urban legends; the effects are painful and can be serious, which is why the poison centres give the instructions above rather than a reassurance.

Dieffenbachia takes shade but grows best in bright indirect light. UConn Home and Garden Education Center says it tolerates a wide range of light and will grow in heavy shade, with the best growth in bright indirect light. Costa Farms, a grower, calls it one of the easiest indoor plants and says it does well in high, medium or low indoor light.

The numbers from UConn:

• Temperature: best growth between 65 and 75 F; do not let it drop below 50 F.
• Water: keep the mix moderately moist; water thoroughly, then not again until the surface is dry to the touch; never waterlogged.
• Feeding: it is a heavy feeder; a complete fertiliser such as 20-20-20 every 4 to 6 weeks, only in the active growing season.
• Mix: loose, fertile and high in organic matter, for example peat and perlite 1:1, or soil, peat and perlite or vermiculite 1:1:1.
• Propagation: tip cuttings, or stem sections cut into 2-inch pieces with at least one bud; tip cuttings root faster than pieces from the base.

On humidity the sources disagree. UConn and Costa Farms suggest a pebble tray; Penn State Extension, cited on our pothos care page, says pebble trays let the moisture diffuse into the room, and recommends grouping plants or a humidifier instead. Our dieffenbachia care guide has the full routine.

None of the extension or poison-centre sources we opened gives a lifespan. Wikipedia describes dieffenbachia as a perennial, and what shortens its useful life indoors is shape rather than age: canes lose their lower leaves and turn into a bare stem with a tuft on top. Clemson Extension's fix, quoted in our care guide, is to cut the stems back to about six inches so the plant regrows below the cut, and UConn notes that tip cuttings from the top of the plant root faster than sections from the base, so the old top can start a new plant. Wear gloves for both jobs.

The sections on handling, naming and care of dieffenbachia were added on 2026-09-25. Research and drafting were done with the help of AI, and every figure was checked line by line against the sources listed on this page.