Dieffenbachias tend to be vigorous growers. Give them a little bit of love, and they’ll sprout into huge canes with broad, luxurious foliage. That’s part of their charm, but it can turn into a bit of a hassle once your plant gets large enough that it’s competing for space with your ceiling fan. We’ll explain how to get a handle on a Dumb Cane that’s grown too tall.
These plants grow back readily from cuttings, so you can cut the stalk back as far as you’d like. Then root the leafy portion you’ve removed in a new pot, wait for new shoots to grow from the base of the original plant, or both! To keep your Dumb Cane short and bushy, periodically snip off the topmost portion of the foliage.
If you don’t mind a tall Dieffenbachia, but you want to keep yours from tilting over, you can easily prop it up with some stakes. The step-by-step instructions we’ve outlined below should give you everything you need to manage your overgrown Dumb Cane.
How Big Do Dieffenbachias Get Indoors?
True to their name, Dumb Canes tend to develop into tall cane plants that resemble stalks of bamboo. They can shoot up two feet or more each year if they’re happy with their growing conditions, and given enough time, they can get quite tall indeed.
The mature height of your Dieffenbachia depends a great deal on which variety you have. Large ones like the Dieffenbachia Snow can get more than six feet tall. If you prefer a shorter plant, you might want to choose one of the smaller cultivars, like Compacta, Camille, or Carina. These tend to limit themselves to a respectable 3 feet or less.
When to Cut a Dieffenbachia
When it comes down to it, only you can decide when the time has come to trim your Dieffenbachia. These plants can be perfectly happy as eight-foot-tall monstrosities that have to stoop under your ceiling. However, there are some points in your Dumb Cane’s life when you may want to consider cutting it down to size.
First of all, you can prune it regularly as a form of preventative maintenance. Trimming away new shoots as they grow from the top of your Dumb Cane’s trunk will keep its height in check and encourage it to sprout more growth off to the sides.
If you don’t prune your plant regularly, it will eventually shed the leaves from the lower portion of the stalk, making it resemble a tree more than a bush. Some owners like this more arboreal appearance, but if you don’t, you can cut back your Dieffenbachia once its trunk starts getting bare.
You might also notice that your Dieffenbachia has gotten top-heavy or developed a twisted stem. Snipping it back is a simple way to resolve these issues.
Once you’ve decided that your plant needs cut, you’ll have the best results if you time the operation for the start of the growing season in early spring. That way, it will quickly start producing new foliage to replace what you’ve removed, minimizing the amount of time you’re forced to look at a hacked-off stump.
How to Cut Back Your Dieffenbachia
Dumb Canes are tough, resilient houseplants, and there’s little risk that you’ll accidentally kill yours with a simple pruning. The following step-by-step guide will explain how to quickly and easily resize your plant.
Step 1: Prep Your Tools
You’ll need a few key pieces of equipment to trim down your Dieffenbachia:
- Pruning shears or a garden knife. A sturdy set of trimmers is often enough to get the job done, but really thick Dieffenbachia stems may require a serrated blade to saw through.
- Gloves. When you cut into a Dumb Cane, it will ooze sap containing nasty chemicals designed to repel herbivores. This fluid can sometimes cause a rash if it touches your bare skin.
- Disinfectant. This one you can probably find at home. You can use rubbing alcohol from your first aid kit or take bleach from your cleaning closet and water it down to 10% strength.
If you’re going to plant the cut stem segment in order to multiply your Dieffenbachia, you’ll also need a pot and some soil. Both should have good drainage – choose a container with holes in the base and a well-aerated potting mix. One easy blend contains 50% coarse perlite, 25% coconut coir, and 25% African Violet potting mix.
Put some of your disinfectant on a clean rag and wipe down your knife or trimmers. This is an important step – you want to kill any bacteria on the blade before you use it to slice into your Dieffenbachia.
Step 2: Make Your Cut
It’s up to you how much of your Dumb Cane’s stalk you want to remove, but you should make the cut just above one of the nodes where new growth emerges. They’re easy to identify – they’re the thin white or brown rings breaking up the green of the stem. Don’t worry if there are no leaves above the node you choose. Your Dieffenbachia will make more soon.
If you want to propagate your plant, take the section you’ve just cut off and trim its base to just below a node. Make this cut at a 45-degree angle to let the stalk absorb as much water as possible while it’s trying to grow new roots. Then leave it out until the next day, someplace warm and out of direct sunlight, to let the cut dry out and seal up.
You can also split the cutting up into multiple smaller stalks to get a bunch of new plants from the old one. Just make sure that each one has a few nodes and not too many leaves.
Step 3: Plant Your Cutting(s)
(This step is optional if you aren’t interested in expanding your Dieffenbachia collection.)
Transplant your cuttings into new pots and pile enough soil around the base of each one to keep it upright. If you can, bury three or four nodes below the soil – this gives the plant more locations to grow out its roots.
Here’s a nifty trick for those interested in giving their Dumb Cane a more full and bushy appearance: you can plant the cutting or cuttings right back into the original pot, giving your solitary Dieffenbachia some company. With several stalks producing foliage at different heights, the overall mass won’t look so bare in the middle.
Step 4: Wait
As we said, Dumb Canes are survivors, and yours should begin putting out new shoots from the uppermost nodes within 3-8 weeks. You should be careful not to overwater the plant or cuttings during this period. With fewer leaves, a Dieffenbachia can’t shed as much water, so the risk of oversaturating the soil is greater.
Moisture in the air is good, though, especially for your cuttings. Give them plenty of humidity to encourage new growth. Setting up a humidifier or a pebble tray is a good idea (see our article on watering and humidity), and you may even want to place clear plastic bags or glass jars over the new stalks to trap as much moisture as possible.
Propping Up a Top-Heavy Dieffenbachia
What if you like your Dumb Cane big and tall, but you’re worried that it’s become too wobbly? Try planting a sturdy stake to give it some extra support. It’s not hard to find purpose-built garden stakes, though you can get perfectly good results with an ordinary wooden dowel too.
Sink your stake deep into the pot an inch or two away from your Dieffenbachia’s trunk, then attach it to the plant with something inconspicuous like twine or garden tape. For extra support, you can place three stakes in a triangle arrangement around the plant.
For tips on preventing your Dieffenbachia from getting leggy and unsteady in the first place, check out our full-length article on the subject.
Congratulations on keeping your Dieffenbachia so healthy that your main concern is that it’s growing too much! This is an easy problem for an attentive houseplant owner to solve. If you follow the advice above, you should have no problem trimming your jolly green giant back down to tabletop size.