Diffenbachia (Dumb Cane)
The first question I get when I show people my big, beautiful Dumb Cane is always, “Why is it called Dumb Cane?” The reason is that the stem of the plant contains toxins that, when chewed, render the person unable to speak as their tongue and throat swells and becomes numb. The first rule of Dumb Cane is: do not keep pets around Dumb Cane.
As far as house plants go, however, the Dumb Cane is really popular because it is visually striking, fast growing, and easy to care for. The plant thrives in indoor temperatures and withstands heat pretty well. I keep mine in an east facing sun room with wall to ceiling windows. The plant grows a full sized leaf and starts on the next one before the last one is even done unfurling. You can see in the below photograph, the new leaf is shooting straight in the air, ready to open.
How to Choose a Houseplant
By the time the new leaf opens, a new shoot will be coming up from the middle. This happens 2-3 times a month, while the plant is also spawning baby plants from the roots. I’ve had this plant for about five months and I’ve separated two spawned plants into separate pots that I will give as gifts as soon as I see them grow a couple of good new leaves.
In the summer months, I water twice a week, but just enough to keep the soil slightly moist. If you overwater a dumb cane, the leaves will turn brown. This is the number one complaint with the dumb cane – it takes a while until you find the sweet spot for your plant. You can see a leaf at the bottom of the plant that clearly didn’t like the amount of water it got.
Underwatering is always better than over-watering. A thirsty plant will look slightly droopy and flat, but usually perks up within a day of being given water. An over-watered plant, however, is subject to root rot and that is hard to overcome.
Note: If you use a copper planter or metal planter, you will want to line the inside with plastic to avoid the rust getting into the soil of your plant. Make sure you poke drainage holes into the plastic. Never keep plants in pots without drainage holes.
Yellow leaves on a dumb cane indicate the plant does not have enough light or too much water. Repeat after me: Always use a little less water than you need. You can always add more later.
Propagating a dumb cane is easy, just wait until the shoots come up on its own, and when you repot the plant, separate the new plants from the mother. If you’d like to propagate from leaves, place the cutting in water and bright light with some root hormone until you see good roots and are ready to place in soil.
There is not much need to prune the dumb cane unless you decide you’d like to cut it back. These plants grow large, beautiful leaves so if you’ve got a space constraint this is not the right plant for you. My plant has tripled in size in five months. I can’t wait to see how big she will grow.