Dieffenbachia spp.
I don’t know about you, but there are days when I just want a houseplant that makes me feel like I’m the most talented gardener on the planet.
If you’re like me and you enjoy easy-care houseplants, say hello to Dieffenbachia, also known as dumb cane.
Showy and elegant, its patterned foliage will add color and dimension to your home.
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Dieffenbachia will tolerate neglect, over- or underwatering, and just about any level of light. There’s no special pruning or pampering required.
Whether you want a small plant that can hang out on a desk in your office, or some ample, bushy greenery to fill a dim, empty corner of your living room, dumb cane is an excellent choice.
In this guide, we’ll dive into how to care for dumb cane, but as I’ve mentioned, it really isn’t difficult. Here’s what I’ll cover:
What You’ll Learn
Plants in the Dieffenbachia genus are native to the Caribbean, and South and Central America.
They have naturalized in Sri Lanka, Singapore, Malaysia, Samoa, and various islands of the South Pacific, including Hawaii and Fiji.
It was given the common name “dumb cane” because of the affect it has if any part of the plant is ingested.
The plant contains calcium oxalate crystals throughout its leaves, stems, and roots. If eaten, the crystals cause the body to release histamines, which results in swelling of the mouth and throat.
Quick Look
Common name(s): Dieffenbachia, dumb cane, leopard lily
Plant type: Herbaceous evergreen perennial
Hardiness (USDA Zone): 10-12 (outdoors)
Native to: Caribbean, Central and South America
Exposure: Full sun to shade outdoors, bright indirect light to full shade indoors
Soil type: Loose, loamy, organically-rich, well-draining
Soil pH: 6.0-6.5, slightly acidic
Time to maturity: 3-5 years
Mature size: 3-10 feet tall by 2-3 feet wide (depending on variety)
Best uses: Ornamental houseplant, border plantings, accent, ground cover in Zones 10-12
Taxonomy
Order: Alismatales
Family: Araceae
Genus: Dieffenbachia
Species: Amoena, bowmannii, picta, maculata, seguine
This can cause breathing difficulties and in severe cases may possibly lead to death. The irritation of the vocal cords and throat can also render the eater mute.
The oxalate crystals can be so potent that simply touching a cut stem to one’s lips can cause swelling. Symptoms start within minutes and can last for days.
Discovery of this property led to a dark, tragic past for this plant.
It was used to punish Black slaves in the Caribbean, and some ingested it as a way to commit suicide. It was also used at least once to silence a court witness.
Michael G. Kenny, Professor Emeritus of Anthropology at Simon Fraser University, wrote in the Social History of Medicine (Volume 15) that Nazi SS leader Heinrich Himmler proposed using extracts of the plant to sterilize “racially undesirable war prisoners.”
In contrast, many cultures throughout history have used the root, stem, and leaves of dumb cane medicinally as a form of birth control and to treat dropsy, inflammation, gout, and sexual dysfunction.
There are 135 known species in the Dieffenbachia genus, though not all are grown as houseplants.
The species you’ll most commonly see in homes are D. amoena, D. bowmannii, D. picta, D. maculata, and D. seguine.
They range in size from two to 10 feet tall and two to three feet wide, depending on the variety. The leaves are elliptic in shape, and can grow up to 10 inches long.
Leaf patterns may be solid green or mottled, with spots or patches of white, cream, or yellow.
The distinctive leaf patterns have earned it the alternate name of leopard lily.
Flowering is rare if grown indoors, but under the right conditions, plants can produce showy white blossoms that resemble a calla lily. If pollinated, these are followed by bright red fruits.
Over time the lower leaves drop off, exposing the stem, which looks similar to sugar cane.
As the leaves drop, leaving just the top foliage in place, the plant starts to resemble a small palm tree.
Toxicity
In case the warning above didn’t tip you off: watch out! This plant is toxic to cats and dogs, and can cause drooling, vomiting, difficulty swallowing, or even death.
Humans should take care, as well. Keep plants away from young children who like to put things in their mouths.
The sap can irritate the skin and eyes. Wear gloves, long sleeves, and eye protection when working with this plant, to be on the safe side, and avoid touching your face.
How to Grow
Dieffenbachia excels as a container specimen both indoors and out.
If you live in Zones 10 to 12, you can also grow it outdoors in the garden in mass plantings, borders, or as an accent.
After you find a good spot for it to grow in, all you need to do otherwise is provide it with food and water now and then.
Light
Dumb cane prefers partial shade and too much direct light can cause tip burn, so avoid bright, west-facing windows.
They can grow in a spot with around six hours of indirect sunlight, but you need to make a special effort to keep them well-watered, so they don’t get too dry with the additional light.
Dumb canes can also adjust to low light, but they will grow more slowly.
Be sure to rotate plants positioned in low light conditions frequently, to prevent them from reaching for the light and growing unevenly.
Soil
Miracle-Gro Indoor Potting Mix is one of my favorite options because it’s both water retentive and drains well.
It also has built-in fertilizer, so you don’t have to feed your plant again for the first six months after potting up.
You can find six-quart bags of Miracle-Gro Potting Mix available at Home Depot.
Temperature and Humidity
A location where temperatures remain between 60 and 75°F is ideal, but these plants can tolerate cooler temperatures down to 50°F and heat up to 90°F for short periods without suffering.
Dumb cane prefers humidity above around 60 percent, but they’ll do fine in drier air as well.
Water
Allow the top inch of soil to dry before watering, but be sure that you never let your dumb cane sit in soggy soil.
If the leaves start to droop, that’s a sign that you need to give your plant a drink. Check the soil and add water if it’s dry.
To water, soak at the soil level until water runs out of the drainage holes. Remove the saucer and toss the excess water after it is done draining.
Just note that dumb cane leaves can start to turn brown at the tips if the plant isn’t receiving enough water or if the air humidity is too low.
Fertilizer
Dumb canes are heavy feeders, but don’t pull out the fertilizer just yet.
You want to find the right balance between applying so much fertilizer that the plant grows too quickly, and giving it so little that it struggles to survive.
Plants that are growing in low light need less fertilizer than ones placed in brighter light, and they will need little or no fertilizer during the dormant winter period.
Lilly Miller All Purpose Plant Food
Choose a balanced fertilizer like Lilly Miller’s All Purpose Plant Food, available on Amazon.
Dilute in water and apply to the soil every six weeks or so during the growing season.
If you notice curled leaves with brown edges and the soil isn’t extremely dry, you’ve likely added too much fertilizer.
If you use potting mix with added fertilizer, don’t fertilize for the first six months after planting. Otherwise, you can start your fertilizer routine straight away.
Cultivars to Select
Sellers often don’t specify which species they’re selling, though they’ll sometimes describe the cultivar.
It doesn’t really matter much, since they all have the same growing requirements. These cultivars are some of the more popular and pretty options out there.
Compacta
If you have a small, poorly lit corner to fill, ‘Compacta’ (D. maculata) might be just the ticket. It stays much smaller than most other varieties, rarely growing beyond 18 inches tall.
The leaves feature a blotchy, cream-colored pattern along the center of the leaves, with a wide green margin.
You can find plants in six-inch pots available from California Tropicals via Amazon.
Exotica
D. maculata ‘Exotica’ has a more upright growth habit than other varieties and grows up to 24 inches tall.
The leaves are green with a marbled creamy yellow pattern that bears a striking resemblance to the merle pattern seen on the coats of certain types of dogs.
Marianne
Sometimes called ‘Tropic Marianne’ or ‘Maryanne,’ D. maculata ‘Marianne’ grows to about three feet tall at maturity. It has oversized leaves with a creamy center and thin, dark green margins.
Unlike many others on this list, the center of each leaf is a single color that gradually fades into the margin rather than having a marbled or speckled pattern.
Rudolph Roehrs
D. maculata ‘Rudolph Roehrs’ has pale, speckled yellow and white leaves with dark green margins and green veins. The foliage almost looks as though someone splattered it with paint.
This one grows anywhere from four to six feet tall, so it’s better for larger spaces.
Tropic Snow
‘Tropic Snow’ stretches up to six feet tall when it’s full grown.
The leaves of this D. seguine cultivar have a dramatic marbled green center, with dark green midribs and margins.
You can find plants in three-gallon containers available from Fast Growing Trees.
Vesuvius
‘Vesuvius’ is a standout D. amoena cultivar because of its explosively mottled leaves.
The margins are dark green, while the center of each massive leaf has cream, yellow, and light green marbling that varies from tiny pinhead-sized spots to larger patches that nearly cover the entire leaf.
This one grows to an average of three feet in height, but I’ve seen them reach up to five feet in ideal conditions.
Maintenance
There’s no need to prune your dumb cane, but if you find any leaves that are shriveled and brown, yellow, or otherwise unattractive, you can trim them off with a clean pair of clippers.
When my dumb canes start to look like palm trees, I simply cut the stem with a pair of clippers to about an inch above the soil level.
Put the plant in a spot with bright, indirect light and keep the soil moist. Within a few weeks, new growth will emerge from the base of the stem and you can start fresh.
Dust the foliage every few weeks with a damp cloth. Leaves that are covered in a layer of dust aren’t able to photosynthesize effectively.
Repot every year or two to keep your dumb cane happy. If you see roots poking up out of the surface of the soil or ringing the perimeter of the container, it’s time to repot.
I like to poke a finger into the perimeter to feel for roots, or you can pull the plant out and examine the situation once a year or so.
You also want to refresh the soil every two years or so. Old soil tends to get compact and loses nutrients.
Use a new container that is a few inches larger than the existing one.
Place soil in the base of the new container so that the plant sits at the same height it was before, if necessary.
Propagation
There are a number of ways to propagate dumb cane at home, including air layering, via stem cuttings, and by division.
When you cut the roots, stems, or foliage, make sure to start with a clean knife or clippers, and clean your tools thoroughly afterwards.
All propagation should be done in the spring or early summer.
Read our complete guide to propagating dumb cane here.
Transplanting
Ready to put your store-bought Dieffenbachia into a container?
Choose a new pot that is at least as big as the container it was growing in, or you can use one that is a few inches larger.
The container should have at least one drainage hole for excess water to run out of.
Use a loamy, well-draining potting soil that contains peat or coconut coir for your new houseplant.
Place some soil in the bottom of the new container to ensure that the plant is growing at the same depth as it was before.
Make sure the soil in the original container is slightly moist before you start working.
Remove the plant from the plastic nursery pot by gently squeezing the sides to loosen it, and then carefully tug out the plant by gripping it at the base of the stem or stems.
Put the plant in the container and fill in around it with soil. Pack the soil down and give it a good soak, allowing the excess water to drain out of the holes in the bottom of the pot.
Pests and Disease
Dumb cane is a sturdy plant that resists most pests and diseases.
If you keep it healthy by watering well, repotting, fertilizing, and dusting as needed, it should be well on its way to withstanding any potential problems.
Still, there are a few insects and diseases that you’ll want to keep an eye out for.
Pests
The usual houseplant pest suspects can sometimes be found lurking around.
Aphids
Aphids are extremely common both indoors and out.
These tiny pests suck on stems and leaves. As they feed, they secrete a sticky substance called honeydew. If you spot ants on your houseplants, look closer.
There may be an aphid infestation, since ants are attracted to the honeydew. The sticky substance also attracts sooty mold.
Severely infested plants can have yellow spots, yellowing leaves, or stunted growth.
The first line of attack is to take your dumb cane to your shower or sink, if possible, and spray the leaves with a strong blast of water.
If that isn’t possible, neem oil is another treatment option.
Dilute neem oil according to the manufacturer’s directions and spray the foliage, taking care to spray the underside where sneaky aphids may be hanging out. Reapply after a week.
If you don’t have some already, you can purchase Bonide Neem Oil Concentrate at Arbico Organics.
You can learn more about how to control aphids here.
Mealybugs
These small pests from the Pseudococcidae family are soft-bodied insects that are often covered in a fluffy, waxy, white material.
You’ll most often notice this pest on the undersides of the leaves and on the canes, where they suck the sap out of your plant, resulting in yellow leaves and stunted growth.
A bad enough infestation can even kill an entire plant.
If you don’t see a huge number of insects on your plant, dip a cotton swab in rubbing alcohol and wipe it on each individual bug.
If you notice a bigger infestation, it’s time to break out the insecticidal soap.
Arbico Organics carries 12- or 32-ounce bottles of Bonide Insecticidal Soap that you can spray directly on the foliage of your houseplants – be sure to apply to the undersides as well.
You’ll likely need to reapply weekly or biweekly a few times to totally eradicate an infestation.
Read more about controlling mealybugs here.
Spider Mites
These tiny arachnids from the Teranychidae family are also sap-suckers.
You might see the bugs themselves, but they are really small, so it’s far more common to see the fine webbing they leave behind.
They can cause discolored stippling or brown spots on leaves. Foliage may also turn yellow.
Neem oil is an effective control for spider mites.
Learn more about spider mite control here.
Disease
While it isn’t common, it’s not impossible for your dumb cane to fall ill with a fungal or bacterial infection. Here are two common ones to watch out for:
Anthracnose
Anthracnose is caused by the fungus Colletotrichum gloeosporioides. It causes circular tan or brown spots with yellow margins to form on the foliage. Spots may appear water soaked or dry.
Neem oil is a good option to start with. Spray the foliage once every few days for several weeks or until you see healthy, new leaves emerging.
Leaves with holes won’t heal, but yellowing should improve.
Bacterial Leaf Spot
Bacterial leaf spot causes small green or gray circles to appear on the foliage. As the disease progresses, they can become larger and may even merge to form a lesion.
The spots may turn brown or black and the centers may fall out. Impacted leaves may also turn yellow.
This disease is caused by Erwinia carotovora or E. chrysanthemi and, unfortunately, there is no cure.
Remove any infected leaves. If all of the stems or the entire plant begins to show symptoms, you’ll need to throw it out.
Dumb Canes Don’t Ask for Much
Dieffenbachia plants have a lot to offer and they don’t ask for much in return. Give them a home, water, feed them when you water, and they’ll add color and texture to your space.
Honestly, it’s making me consider tossing my orchids out the window (look out below!) and filling my house with dumb canes instead.
What about you? Are you excited to get going with dumb canes? Come back and share with the rest of us about how you do – and be sure to tell me which cultivar you pick!
Feel ready to add more houseplants to your indoor jungle? Here are some other guides that you might find helpful:
Hey my friend gave me a cutting of a flower/pod and I’m just wondering how I’d go about making new plants from it? Thanks Bailey
What does this cutting you received look like? Can you share a photo (click on the paperclip icon at the bottom right to upload)? These plants are usually propagated from vegetative cuttings, and you can find instructions in our guide. Flowering is rare in dumb canes grown indoors, and when they do bloom, these produce flag-like spathes with a central spike-like spadix covered in teeny-tiny blooms, similar to what you might see in peace lilies or anthuriums. If the flowers are pollinated and fertilized, dumb cane flowers produce clusters of red or orange fruits that contain the seeds, rather than… Read more »
My dumb cane has two stems that have turned yellow, feel hollow at the touch, have flowers at the top with a little green coloring stem. Should I cut the yellow stem at the soil level or remove those stems out of the pot? What has caused the stems to loose its green color?
Hi Anita, a dumb cane might turn yellow for a number of different reasons. In this case, I would suspect that the plant is shedding older growth to focus on newer growth. I’d also check the soil to see how moist it feels all the way to the base of the pot. Cut off the yellow stems since they’re just a drag on the plant.