The most common problem with dieffenbachia (and the reason it doesn’t quite make it onto my list of easy-to-grow houseplants) is leaf burn due to fluctuations in fertilizer and light levels. These issues, along with too little moisture, can all cause dieffenbachia leaves to turn brown.
So, why are my dieffenbachia leaves turning brown? Too much fertilizer, uneven watering, low humidity, and/or inadequate sunlight are the usual culprits. Dieffenbachia needs a consistent feeding schedule, moist soil that never dries out completely, moderate humidity, and bright indirect light to thrive.
In this post, we’ll take an in-depth look at these problems, including how to fix your brown-leaved dieffenbachia and bring it back to health. If you need more help caring for your plant, check out my complete Dieffenbachia Plant Care Guide.
Too Much Fertilizer
If your dieffenbachia leaf edges turn brown and curl, this is most likely leaf burn caused by too much fertilizer. You can fix over-fertilizing by leaching the pot to remove excessive fertilizer salts. Flush the soil thoroughly with clean water, allow it to drain for about 30 minutes, then repeat.
After two weeks, resume a regular feeding schedule to prevent the issue from happening again. Feed once every two weeks in spring through summer with a balanced houseplant fertilizer. Reduce feeding to once a month during fall and winter.
My favorite fertilizer for dieffenbachia is Jack’s Houseplant Special. It has a micro-nutrient ratio formulated to produce strong roots and green foliage. It won’t build up in the root zone and cause fertilizer burn like some other products out there.
Not Enough Water
Not watering enough can also cause dieffenbachia leaves to turn brown, starting with the leaf tips. Drooping leaves are also an indication of under-watering. Although this plant adapts easily to most indoor conditions, it still needs moderate humidity and slightly moist soil.
I typically water my dieffenbachia a few times a week, but I live in a very dry area. If the air in your home is more humid, you may only need to water once a week. To know for sure when your specific plant needs water, check the soil moisture daily.
Insert your finger into the soil. If it feels dry to the touch, water thoroughly. If the soil still feels moist under the surface, wait until the next day and check again. Your plant may need more water at certain times of year than others, depending on the conditions in your home.
Low Humidity Levels
Dieffenbachia needs moderate humidity levels to really thrive. If the air becomes too dry, your plant will let you know. Leaf edges turning brown are a common sign. Here are some tips for raising humidity for your dieffenbachia (and any other houseplants):
- HUMIDITY TRAY – Place the plant on a water-tight tray filled with pebbles and water. See my post on how to make a humidity tray for houseplants for more information. Make sure the water stays below the pebbles, so the bottom of the pot does not touch the water.
- REGULAR MISTING – Mist your dieffenbachia using a spray bottle filled with room temperature water a few times a week to increase moisture in the air.
- HOUSEPLANT HUMIDIFIER – Place a high-quality humidifier in the same room as your dieffenbachia. I like the Honeywell Cool Mist model best. Using a humidifier is a good idea if you grow houseplants and live in a dry area (like I do).
If you don’t have access to a humidifier, see my post on How to Increase Humidity for Houseplants Without a Humidifier for more ideas. In most cases, a humidity tray and/or regular misting will be sufficient for dieffenbachia. But if you want to go the extra mile, a humidifier can help.
Too Much Sunlight
Too little sunlight is another reason for dieffenbachia leaves turning brown. Exposure to direct sunlight can burn the delicate foliage, especially hot afternoon sun from a south- or west-facing window. To keep dieffenbachia happy, provide bright, indirect light only.
The ideal location is in an east- or west-facing window with the light filtered by sheer curtains. You can also place dieffenbachia a few feet back from a south-facing window or in a north-facing window with no curtain.
How I Fixed My Dieffenbachia Leaves Turning Brown
I had the worst time with my dieffenbachia when I first brought it home. I placed it in an east-facing window and still had so many issues with the leaves turning yellow and brown, and dropping off. But I finally figured out a way to make this finicky houseplant happy…
Artificial lights.
The light from the east-facing window was still scorching my plant’s leaves – even though it was cool morning sun. I live at a high altitude, so maybe this was the reason. I’m still not entirely sure, but I definitely recommend trying artificial lights if you have similar issues.
My dieffenbachia is now producing so much beautiful foliage and no longer has brown leaves EVER. I’m using this artificial plant light from Amazon. I could tell a difference in my plant’s health after about a week, and in a month it was likely a completely new plant!
I run the light for 8 hours a day (it comes with a handy automatic timer), and my dieffenbachia plus all my other houseplants are thriving under it.
Related Questions
Here are some frequently asked questions related to dieffenbachia leaves turning brown that you might find helpful (plus my answers to them).
Should I Cut Brown Leaves Off Dieffenbachia?
Yes, you can remove brown leaves from your dieffenbachia if the entire leaf has turned brown. Snip off the leaf at the base of the stem using a pair of clean, sterile scissors or pruning shears. Wear gloves and wash the scissors thoroughly afterward, as the toxic juice from dieffenbachia leaves can irritate skin and mucous membranes.
How Often Do You Water a Dieffenbachia?
Water your dieffenbachia any time the top 1 inch (2.5 cm) of soil becomes dry. In my home, this is about once every 3 or 4 days, but I live in the desert. If you live in a more humid climate, you may need to water less frequently.
To keep your dieffenbachia happy, check for soil moisture daily. Insert your finger into the soil to a depth of 1 inch (2.5 cm). If the soil is dry, water thoroughly. If the soil is moist, wait until the next day and test for moisture again.
How Do You Revive a Dying Dieffenbachia?
You dieffenbachia can usually be saved if it’s not too far gone. If it still has some green growth, you can most likely revive it. Here’s what to do:
- Place the plant in an area that receives bright, indirect light, like an east-facing window or under artificial lights.
- Water thoroughly if the plant is dry or stop watering if the soil is wet.
- Increase humidity around the plant by misting or placing on a humidity tray.
- Feed every two weeks with a balanced houseplant fertilizer if your plant hasn’t been fed in a while. If it’s been over-fertilized, leach the pots to remove accumulated fertilizer salts.
Once you start providing proper care for your dieffenbachia, it should start improving within a few days. It may take a couple weeks to return to full health. But I have personally saved a dying, drooping, yellow-leaved dumb cane this way – so I know you can do it too!
Why is My Dieffenbachia Plant Turning Yellow?
The most common causes of yellowing leaves are too much water, too much sunlight, and low temperatures. Some pests may also cause leaves to turn yellow, and rarely, nutrient deficiencies or plants being root-bound may be to blame.
See my post on How to Help a Dieffenbachia With Yellow Droopy Leaves for more help with this problem. Good luck and happy growing!
