Dumb cane
Sources last read 14 September 2026.
Middling It gives warning, with time to act.
Also called Dieffenbachia, Dumbcane, Gold Dieffenbachia, Spotted Dumbcane and Variable Dieffenbachia.
Dumb cane is toxic
- Toxic to cats. Toxic principle: Insoluble calcium oxalates, proteolytic enzyme. Clinical signs: Oral irritation, intense burning and irritation of mouth , tongue and lips, excessive drooling, vomiting, difficulty swallowing. ASPCA ASPCA names the genus (Dieffenbachia), not the species.
- Toxic to dogs. Toxic principle: Insoluble calcium oxalates, proteolytic enzyme. Clinical signs: Oral irritation, intense burning and irritation of mouth , tongue and lips, excessive drooling, vomiting, difficulty swallowing. ASPCA ASPCA names the genus (Dieffenbachia), not the species.
- Toxic to people. Toxic when eaten; irritates skin and eyes. Use gloves and protective gear when handling it. RHS
What the sources say about its care
Sources file this plant under other names: Dieffenbachia (ASPCA, genus only), Dieffenbachia maculata (Clemson Extension). Citations below point at the name its source uses.
- Light
- Medium light 100–150 fcClemson Extension, filed as Dieffenbachia maculata · read 13 September 2026Full sun, Partial shadeRHS · read 13 September 2026
- Water
- Moist but well-drained or Well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H1A — warmer than 15°C 15 °CRHS · read 13 September 2026- Soil
- Loam, Sand; pH Acid or Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- ToxicASPCA names the genus (Dieffenbachia), not the species.ASPCA, filed as Dieffenbachia · read 13 September 2026
- Toxic to dogs
- ToxicASPCA names the genus (Dieffenbachia), not the species.ASPCA, filed as Dieffenbachia · read 13 September 2026
- Harmful to people
- Toxic when eaten; irritates skin and eyes. Use gloves and protective gear when handling it.RHS · read 13 September 2026
How it usually goes wrong
- Leaf tips go crisp and brown
On a dumb cane the browning starts furthest from the midrib and works inward, and it crumbles rather than smears. The centre of each leaf is untouched.
Transpiration rises as the air dries, and the tissue furthest from a vein loses first. Penn State Extension notes there is no single humidity figure that suits every indoor plant, which is why this site publishes a range rather than a number.
Telling it apart: Whether the soil is dry too. Crisp edges with damp soil point at the air; with dry soil, at the watering.
Penn State ExtensionDumb cane brown leaf tips and edges: causes- Lower leaves collapse and yellow within days of a watering
On a dumb cane the yellowing climbs from below. Affected leaves feel limp rather than papery, and water sits in the saucer long after it drains through.
The source for this plant describes moist but well-drained or well-drained soil. Compost that stays saturated loses the air spaces fine roots grow into, and those roots die back first.
Telling it apart: Weigh the pot in your hand. A pot still heavy a week after watering is holding more water than the roots are using.
RHSDumb cane leaves turning yellow: causes- Pale, undersized leaves at the tips of the stems
Older leaves on the dumb cane keep their colour while each new one comes in thinner, with a longer stretch of bare stem below it.
Placed darker than the medium light its source describes, the plant invests in length rather than leaf, because length is what finds a window.
Telling it apart: Whether old growth is affected. Light shows in what arrives next; feeding shows in what is already there.
Clemson ExtensionDumb cane leaves turning yellow: causes
Not sure which it is? Ask the diagnosis questions for Dumb cane.
Routine care
- Watering
- Water thoroughly, then wait until the top 1 inch of soil is fully dry before watering again.NC State Extension · read 13 September 2026While growing, water moderately, feed monthly with a balanced liquid feed and mist every day to raise humidity. In winter, give little water and full light.RHS · read 13 September 2026
- Feeding
- While growing, give moderate water and a monthly balanced liquid feed; mist every day to raise humidity.RHS · read 13 September 2026
- Propagation
- Use division, stem cuttings or root cuttings to propagate.NC State Extension · read 13 September 2026Root stem-tip cuttings, or lay stem sections that each have a growth bud flat on the compost surface at 25°C. Air layering also works.RHS · read 13 September 2026
- Pruning
- Pruning is not needed.RHS · read 13 September 2026
- Pests and diseases
- Can be troubled by brown soft scale, aphids, fungus gnats, greenhouse whitefly and armored scale.NC State Extension · read 13 September 2026New growth in particular can attract aphids. Diseases: usually none.RHS · read 13 September 2026
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Photographs
About the plant
Dieffenbachia seguine, widely known as dumbcane, as well as leopard lily or tuftroot, is a species of Dieffenbachia, a flowering aroid plant of the family Araceae. It is native to the neotropical realm of the Americas, from extreme southern Mexico and Belize and much of Central America, as well as the northern half of South America. It is found on many Caribbean islands and territories, including Cuba, Grand Bahama, Grenada, Guadeloupe, Hispaniola, Îles des Saintes, Jamaica, Martinique, Puerto Rico, Saba, Saint Kitts and Trinidad and Tobago. D. seguine is also found on the Galápagos islands of Santa Cruz and San Cristóbal, where it was likely introduced by humans.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- Caribbean to S. Trop. AmericaWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Caribbean to South Tropical AmericaNC State Extension · read 13 September 2026
- Climate
- wet tropicalWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- subshrubWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Herbaceous Perennial; habit erectNC State Extension · read 13 September 2026Bushy (evergreen)RHS · read 13 September 2026
- Size
- Height 36–96 in; width 24–36 inNC State Extension · read 13 September 2026Height 2.5-4 metres; spread 0.5-1 metres after 10–20 yearsRHS · read 13 September 2026
- Flowering
- Flowers green, insignificant, white; blooms in spring, summerNC State Extension · read 13 September 2026
Common problems with Dumb cane
More of the Araceae family
Arrowhead plantEdges of the leaf blades brown while the middle stays sound
Calla lilyEdges of the leaves brown while the middle stays sound
Elephant earCrisp margins that appear in winter
Flamingo flowerBrown brittle margins with a green centre
Heartleaf philodendronA thin dry rim that crumbles between the fingers
MonsteraBrown brittle margins with a green centre
Plants with similar care
Sources
- ASPCA · read 13 September 2026
- Clemson Extension · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.