How to Grow and Care for Dieffenbachia
Dieffenbachias feature pointed, ovate leaves in a variety of combinations of green, cream, and white colors. A large, well-grown dieffenbachia can reach 10 feet, with leaves 20 inches long. However, the plants will rarely reach this size in typical indoor conditions, where 3 to 5 feet is more common. 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 is highly toxic to humans, dogs, and cats.
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.
Dieffenbachia is best grown as an indoor plant in bright, indirect sunlight. Plant it in fertile, well-drained potting soil with a high peat content. As a tropical plant, it will do best in high humidity. One way to provide this is to place the pot on a tray of pebbles that is kept wet. Misting the leaves can help during the dry winter months.
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.
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.
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.
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.
For best results, feed regularly (every four to six weeks) with a balanced, diluted fertilizer, such as a 20-20-20. However, some growers swear by a routine of using a weak diluted fertilizer at every watering.