Dieffenbachia (Dumb Cane) Plant Care and Grow Guide

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The Dieffenbachia, also known as the “Dumb Cane,” is one of the most popular houseplants around.

The Dieffenbachia genus calls the Caribbean and South America its home. It’s a member of the Araceae family and refers to quite a large group of tropical plants that are perennials.

You may find some members of the dieffenbachia group with other names, however, collectively they are known as dieffenbachia or the “dumb cane.”

Why “dumb cane?” An unusual name at the least for a plant. This name originates from the fact that chewing it will cause the tongue to swell. With a swollen tongue, it’s quite difficult to speak, and so its name was born.

This article discusses how to care for the dumb cane and successfully grow it.

Dieffenbachia (Dumb Cane) Overview

Dieffenbachia is characterized by large ovate leaves that are pointed. Leaves will feature various combinations of white, cream, and green in their patterns. Its lush leaves also help purify the air by removing toxins.

This lovely plant is a fast grower. If you plant a dieffenbachia with roots and position it to receive a good amount of light, it can grow as much as two feet in one year alone.

Large dieffenbachia plants can grow to heights of ten feet and a single leaf can be twenty inches long. If you are growing a dieffenbachia plant indoors, the more common height is three to five feet tall.

This group of plants boasts more than thirty different species and more than a hundred various cultivars.

The most common dieffenbachia varieties include:

  • Dieffenbachia Seguine variety is native to Brazil and features clusters of large luscious green leaves with beige or white splotches. This plant can grow to a height of ten feet.
  • Dieffenbachia Oerstedii is characterized by large oval green leaves that will feature patterns in green and white
  • Dieffenbachia Maculata, also known as dieffenbachia picta, includes several versions. “Perfection” boasts leaves of about eight inches that are incredibly variegated. “Rudolph Roehrs” will feature yellow leaves with cream-colored splotches and “Superba” has white variegation on leaves that are thicker. The “Camille” has yellow leaves with white edges, and it can grow to three feet.
  • Dieffenbachia Amoena is a large version at about six feet with leaves that grow to twenty inches. A notable amoena is the “Tropic snow” that will feature more variegation and somewhat smaller leaves.

Dieffenbachia Plant Care

This is a relatively easy plant to grow indoors, and it makes quite an impression as part of your home or office decor. For the dieffenbachia to be happy and healthy, it will require good light, relatively high humidity, and above all, regular watering.

Soil for the Dieffenbachia

The soil bed for the dieffenbachia should be fertile potting soil that drains well. Drainage must be good because soil that is soggy will inevitably damage the roots. A high peat content will contribute to its general health. Soil pH should be slightly acidic in the range between 6.1 and 6.5.

Most potting soil mixes that are sold will be made with sedge peat or reed, and then pH improved with lime. Bagged soil will often appear loamy and rich when you open the bag. They may also be enriched with crystals for water retention or even fertilizer or organic material.

Potting soil is not made for long-term planting and feeding. After a growing season, they will usually have used up their nutrients. An annual change of the soil is still recommended. 

Peat will decompose rapidly, so after about a year, your potting soil has very little to offer. The immediate problems include:

  • Soil becomes compressed – If your dirt looks as if it’s settling, it’s probably decomposing and will pack itself around the roots impeding access to oxygen and slowly killing your plant.
  • Water can’t drain – If the soil reverts to small particles, it will make it difficult for the water to drain through. If drainage slows or is impeded, it may favor the buildup of salts and fertilizing components, scorching the roots and stressing your plant.

You can opt to make your own potting soil to enable it to last longer. If you want a home soil recipe, try one part peat, one part garden soil, one part sand or perlite and a pinch of lime. 

Temperature for the Dieffenbachia

As a tropical plant, the dieffenbachia likes a warmer environment. An ideal temperature should fall between 65° and 75° Fahrenheit.

If your plant experiences a drop in temperature below 60°F, it may lose its lower leaves and look like a palm with a top canopy. The same thing will happen if it is exposed to cold or cooler drafts.

Light for the Dieffenbachia

Ideal lighting conditions for the dieffenbachia are bright, but indirect light. As indoor plants, they thrive in shady conditions. 

Since the plant will grow in the direction of the bright light, it is a good idea to rotate it from time to time, so that growing maintains a certain balance.

Water and Humidity for the Dieffenbachia

Being a tropical plant, high humidity will make for a happy dieffenbachia plant. One way to help produce moisture for the dumb cane is to place it on a tray filled with pebbles and water. The water will help with adding humidity.

During the winter months, especially if indoor heating causes dryness in the air, it’s a good idea to mist the leaves with a spray bottle. You can also get a humidifier to add humidity.

Overwatering is, as with many various houseplants, a risk for dieffenbachias as it can lead to root rot. Be sure that excess water can drain out through the bottom of your flowerpot. 

If your plant is large it may need to be watered twice weekly. In the winter months, watering should be cut back considerably. Top soil must dry out before watering again. Two inches of topsoil should dry out before you water again. 

Another good habit will be to flush out your dieffenbachia’s soil once a month. Take your plant to a sink or outdoors with a garden hose and literally flush the soil out to remove salt or fertilizing chemicals that have accumulated in the soil.

Let it drain thoroughly before replacing it in a plant holder. You can also insert a wick in the drainage hole at the bottom of the pot to help drainage.

Fertilization for the Dieffenbachia

The dieffenbachia plant likes to eat, so it should be fertilized once every four to six weeks. A balanced 20-20-20 water-soluble fertilizer that is diluted will do the trick.

Some gardeners actually fertilize at every watering, but with very, very diluted, weak fertilizer to avoid scorching roots. 

Pruning and Repotting the Dieffenbachia

If you notice that your dieffenbachia’s lower leaves are looking a bit sickly, remove them while your plant continues to grow. You can achieve a nice canopy that arches, so don’t fear removing those lower leaves.

If you leave your plant unpruned, it will take on the appearance of a palm tree.  When pruning, wear gloves and water the plant once you have finished.

The nicest thing you can do for your dumb cane is to repot annually. This is a practical and pretty easy choice to keep your plant healthy. In the short term, you can add a few fistfuls of perlite to increase aeration until you repot.

To prevent the dieffenbachia from growing to appear leggy, just prune or pinch any new growth at the top on a regular basis. This will encourage a bushier kind of growth. If you feel your plant is too tall, you can top it, cutting it back anywhere along its stem.

Propagating Dieffenbachia

A dumb cane can be propagated in several ways. Here are three common ways:

  1. Take several pieces of cut cane and lay them horizontally in a container with damp potting soil. Once the pieces develop roots, leaves will begin to sprout.
  2. If your dieffenbachia is an older plant and appears leggy, you can cut off the top of the plant and place it directly in fresh potting soil together with rooting hormone. Eventually new leaves will begin to sprout from the transplanted top. When the new leaves appear, you can remove old leaves and discard.
  3. When you repot in the spring, any offsets can be divided, but they should have some roots. They should be planted in new pots. It is vital that the roots of the parent plant are not damaged during the division. Use tools that are sterilized, so that no disease is spread during the division.

The dieffenbachia will not root in water, so be sure to use soil. 

Dieffenbachia Pests, Diseases, and Problems

Dieffenbachia plants are relatively free from problems, however, it can be at risk for some pests.

Spider mites will cause leaves to turn pale and a webby substance can be found on the underside of the leaves. Mealy bugs will leave cottony deposits on leaves.

If you see pests, you can treat your plant with neem oil or another horticultural oil, as opposed to using chemical pesticides. Pests can also be washed off with strong water spray.

If your plant is dying due to overwatering, you should remove the plant from all the wet soil. Remove any dead leaves or dying leaves from the plant.

Leave the plant laying out for twenty-four hours while it is bare rooted. The roots should be able to dry out.

Place the plant in new potting soil in a correctly sized pot. Do not water again for seven to ten days.

Yellow leaves on a dieffenbachia indicate one of several things:

  • The pot is too large for the plant. In this case, the soil may have difficulty drying out adequately. A pot should be approximately one to two inches wider and deeper than the root ball.
  • Exposure to a cold draft or a vent for air conditioning
  • Bottom leaves may not be receiving sufficient light
  • The soil is too dry

Droopy leaves indicate too little water. If, however, the leaves droop and drop off without becoming yellow, the plant is probably too cold.

Brown tips on the leaves indicate watering that is uneven.

Curled leaves with edges that are brown may be caused by too much fertilization.

If your plant shows little new growth, it may not be receiving adequate light. Consider moving it that offers more light.

Diseases that can affect your dieffenbachia include:

  • Root rot
  • Leaf spot
  • Stem rot
  • Petiole rot
  • Erwinia blight

Dieffenbachia Toxicity and Pets

The dieffenbachia is toxic to pets and humans. The leaves contain calcium oxalate in the form of crystals known as raphides. They can affect discomfort and more through ingestion and touch. 

Chewing on the dumbcane plant leaves can lead to swelling and severe burning in pets. Should symptoms appear severe, you will need to get your pet to a veterinarian as soon as possible.

If you are at risk for coming into contact with the plant’s sap when pruning, potting, repotting, or other, always wear gloves.

Dieffenbachia Poisoning Symptoms

The raphides within the plant’s leaves will cause swelling and burning of the mouth, tongue, throat, and skin of animals and humans. In some cases, the swelling can become so severe that a person will have difficulty talking

It can also impede breathing, potentially causing death. Death would be unusual in humans, but there have been cases of very young children dying.

Generally, humans and animals will stop after the first bite due to the unpleasantness experienced. Death is more common in domestic pets if they chew on the leaves.

Should a pet or small child place a dieffenbachia leaf in the mouth, the mouth and any exposed skin should be rinsed immediately. Should discomfort and swelling begin, a doctor or veterinarian should be contacted without any delay.

Dieffenbachia (Dumb Cane) Care Final Thoughts

The dieffenbachia is a beautiful houseplant that can bring color and elegance to any location. It is not as easy to care for as other houseplants, and as such is a better choice for home gardeners with a bit of experience to guarantee the plant’s survival and that it flourishes.

Take a look at other houseplant care guides to beautify your home: 

Dieffenbachia (Dumb Cane) FAQs

Why is the dieffenbachia dangerous?

Dieffenbachias are dangerous because they’re poisonous plants. Their leaves contain calcium oxalates which irritate the mucous membranes of people and animals who come into contact with them. In some cases, that can lead to swelling in the mouth and throat, leading to the inability to breathe.  

Can the dieffenbachia kill you?

Yes, dieffenbachias and their toxicity can lead to death. If ingested, the effects could range from mild irritation to respiratory failure. Other common results are vomiting, coughing up blood, hives, or diarrhea.

Why are the leaves on my dieffenbachia turning yellow?

The leaves on your dieffenbachia plant could be turning yellow for a number of reasons. The pot is too large for a plant. The soil may not be able to dry out adequately or the soil may be too dry. Another reason is the bottom leaves aren’t receiving enough light. It could also be experiencing a cold draft that’s giving it a shock.

How often should I water my dieffenbachia?

Water the dieffenbachia once every two weeks during the summer months. During winter, give them about half-waterings twice per week. You’ll want to keep an eye on how much moisture your dieffenbacias need. You don’t want to overwater them, but you also want to ensure they get enough water. They like moist conditions. 

How much sun does a dieffenbachia plant need?

A dieffenbachia needs bright sunlight throughout its growing season, about six hours each day. However, this doesn’t mean you shouldn’t provide shade when necessary. A shady spot near windows or under trees works well.

Is the dieffenbachia an air purifier?

Yes, the dieffenbachia plant purifies the air by removing toxins and pollutants through its leaves. This helps reduce allergies and asthma symptoms among those around it.

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Written by:

Amy Walsh
Amy Walsh is a passionate indoor gardener, deeply engrossed in the world of houseplants and herbs. Her apartment is a lush sanctuary of foliage, reflecting her journey from hobbyist to devoted botanist. She's constantly exploring the latest in smart garden technology, eager to share her insights on nurturing green spaces indoors. Alongside her botanical pursuits, Amy enjoys connecting with nature and friends, continually enriching her lifestyle with greenery and growth.

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