Dieffenbachia is a fast-growing plant that can achieve 2 feet in height within a year of planting a rooted cutting, provided it gets enough light. Though the name “dumb cane” has fallen out of favor as a derogatory term, it was called that because the plant contains toxins that can inhibit speech. It is highly toxic to humans, dogs, and cats. Like many indoor houseplants, overwatering is a common problem with this plant. Allow the top 2 inches of potting soil to dry out completely before watering thoroughly so that moisture drains through the bottom of the pot. If you wish, lower, weak leaves can be removed as the plant grows, creating a specimen resembling a small palm with an arching canopy.
Light
Dieffenbachia plants are popular indoor plants largely because they do well in shady conditions, but these plants do appreciate bright light during the winter months. During the growing season, the plant prefers dappled shade or indirect light. The plant will favor the side facing the light, so periodically rotate the plant to keep its growth balanced.
Soil
Use a fast-draining, well-aerated potting mix. Make sure drainage is good to avoid damaging the roots; they should never be left in soggy soil.
Water
During the growing season, dieffenbachias like regular moisture and do not want to dry out. A large dieffenbachia might need to be watered twice a week. In the winter, you can cut back on the water. At the same time, it’s important not to overwater a dieffenbachia, which can cause rot problems. Make sure the top of the soil is fully dried out before watering.
Temperature and Humidity
This plant likes fairly warm conditions, from 65 degrees to 75 degrees Fahrenheit. If the temperature drops below 60 degrees or if the plant is exposed to cold drafts, it is likely to lose lower leaves and assume a palm-like appearance.
Fertilizer
For best results, feed regularly (every four to six weeks) with a balanced, diluted fertilizer, such as a 20-20-20. For the amount to use, follow product label instructions. However, some growers swear by a routine of using a weak diluted fertilizer at every watering.
Types of Dieffenbachia
The Dieffenbachia genus includes a large group of beautiful tropical perennials, but the ones most commonly grown in cultivation are D. sequine, D. oerstedii, D. maculata, and D. amoena. Several Dieffenbachia species have recently been reassigned with different names, so you may run into confusion on the precise naming of different varieties. Collectively, they are generally known as dieffenbachias or dumb canes. Of the many species of Dieffenbachia, only a few are commonly sold commercially:
D. seguine, the most popular Dieffenbachia species, is a native of Brazil with clusters of large ovate leaves with green margins splotched with yellow or cream color. It can grow as tall as 10 feet.D. maculata (formerly known as D. picta), offers good cultivars that include ‘Perfection’, with intensely variegated 8-inch leaves; ‘Rudolph Roehrs’, with fully yellow leaves with ivory splotches; and ‘Superba’, with thicker leaves and white variegation. ‘Camille’ has pale yellow leaves with white margins and grows to about 3 feet.D. amoena is a large, 6-foot plant with 20-inch leaves. One notable cultivar is ‘Tropic Snow’, which has smaller leaves and more variegation.
Propagating Dieffenbachia
There are three easy ways to propagate a dieffenbachia plant. To divide by root division: To propagate a stump: To propagate with cane cuttings:
Potting and Repotting Dieffenbachia
Dieffenbachias often need annual replanting. Watch out for signs of stress on the plant, such as roots poking out from the surface, crowding, or falling leaves, which could signal that the plant needs repotting. To repot, simply lift the plant as a whole, knock away any old soil and dead material from the roots, and place it in a larger container with some added fresh soil. After repotting a dieffenbachia, give it some time to adjust to its new setting. Wear gloves to avoid contact with the sap.
Common Pests
Dieffenbachia plants are largely trouble-free, but like many indoor plants, they can be susceptible to spider mites. These can be treated with a horticultural oil.
Common Problems With Dieffenbachia
You will be able to tell a lot about your dieffenbachia by the state of its leaves. Watch for certain colorations on the leaves to let you know what to do to amend conditions.
Leaves Turning Yellow
Overwatering or underwatering your plant can turn the leaves yellow. Often, they will also fall off the plant. Check the soil by sticking a finger into the soil up to the first knuckle. If it’s wet, hold off on watering for a week or so. You may have to go a little deeper to see if the soil is too dry, which means you need to add water to the plant. Cut off the yellow leaves regardless of the reason. Leaves could also turn yellow because the plant is lacking nutrients, such as nitrogen. Though this can be tough to diagnose, it won’t hurt to use a plant fertilizer to see if will bring your plant back to health.
Drooping Leaves
Dieffenbachia prefers partial shade. If your plant droops, it may mean it’s getting too much sunlight. Move the plant to a spot with indirect sunlight. However, if it’s not getting enough light, the leaves may turn yellow and droop. Move it to an area with a bit more light to alleviate this problem. The plant may droop because it is cold or near a draft. Keep your plant in a consistently warm area that’s between 65 degrees to 75 degrees.
