ZZ plant's stem can turn brown for various reasons, including overwatering, exposure to direct sunlight, fungal attack, and too much fertilizer.
You can fix this issue by adjusting your watering routine or moving your plant to a shadier location. But there's more you can do to prevent this from happening again in the future.
Let's take a deep dive into this issue in the following guide.
Why Is My ZZ Plant Stem Turning Brown?
If you're a new plant parent, you might feel overwhelmed to see stems changing their color within a few days. But it generally happens due to some of the common gardening mistakes.
Let's quickly take a look at them below.
1. Overwatered ZZ Plant
Have you been watering your ZZ plant regularly?
If the answer is yes, this will likely cause the brown stem on your ZZ plant. This plant doesn't need a lot of water.
Unlike most indoor plants, the water requirements of this plant are pretty low. If you overwater the plant, it will cause rotting issues on the stem and the roots. Similarly, if you have been misting this plant, it can lead to a similar problem.
2. Direct Sunlight
Another thing that makes life difficult for the ZZ plant!
If you have been growing this plant in a bright and sunny place, it will cause a stem burn or leaf burn on the plant. The brown color on the stems could result from overexposure to the sun. When the sunlight drops on these delicate parts, the plant depicts this behavior.
3. The Stems Might Be Turning Old
Well, it may not be the most probable reason for this cause, but you should check your plant thoroughly before ruling out this possibility.
If you have been growing this ZZ plant for a few years, you might see some stems turning brown due to aging. It's the natural way of the plant to get rid of the old parts and make way for the new ones in the process.
4. Overfertilized ZZ Plant
Even though fertilizers are great for the plant's growth, they can cause severe damage if used incorrectly.
Overfertilization is the worst thing to happen to a thriving plant in your home garden. So, check whether you have been fertilizing your ZZ plant every month.
If you have fertilized it multiple times in a short period, you will see some of its effects on the stems and roots. Sometimes, you might also see yellow leaves on this plant, which is another indication of the same issue.
5. Fungus Attack
It's the most damaging factor that can make your ZZ plant stem turn brown.
If this is the case with your plant, the brown stem only indicates what's coming next for the plant. When the stems change their color to brown, the fungus spreads on the plant.
In a few weeks, it will take over the entire plant. Then, you will see many stems turning black and wilting in the same period. And that's something you want to avoid at any cost.
If you don't intervene at this stage, the plant will succumb to the damage caused by the fungus problem.
In the following segment, you will find useful tips to resolve this issue and revive the plant simultaneously. Do check out these suggestions and implement them as early as you can.
How To Fix The ZZ Plant Brown Stem Issue
Here's the list of tips for you -
1. Use Fungicides To Remove The Fungus
Fungicides effectively stop the overgrowth of the nasty fungus, which makes the job a little easier while carrying out this task.
There are many fungicide products available in the market. You can get the ones that are suitable for indoor plants.
As for the usage, you will be able to see the guidelines or instructions on the package. Follow those guidelines and spray them on the plant and soil accordingly. You can also use Neem Oil for this process, which is an organic fungicide for plants.
Important: Do not expect quick results with this process. This type of issue surfaces again even after the initial spray.
So, you might need to spray your fungicide once again after a week. It will ensure the complete eradication of fungus on the plant. That said, do not use a concentrated spray for a better effect. It won't harm the plant and may result in leaf or stem burn.
2. Overturn The Soil For Fungus Growth Prevention
Once you are done with the above important task, you can use a shovel or spade and try to overturn the soil in the pot. It's an essential step in this process because it helps prevent fungus growth.
When you stir the top surface of the soil, it exposes the moist soil to air and light. Eventually, the soil dries out quickly and stops the fungus growth present on the surface.
3. Stop Overwatering Your ZZ Plant
It's pretty much self-explanatory now. You should never overwater the ZZ plant.
If you have overwatered the plant, you should either repot or transplant it quickly. It won't be a great idea to keep growing your plant in the same soil.
Also, if the soil is moist, do not water the plant for at least a few weeks. Let the soil turn dry before you water the plant for the next round.
4. Move The Plant To A Shaded Place
Exposure to direct light can also cause this plant to have brown stems. So, it would be best to move it to a place that doesn't receive too much sunlight.
This is an ideal condition for the ZZ plants you grow indoors. It may do alright with some indirect sunlight, but it always avoids harsh sunlight.
5. Keep It In A Slightly Humid Place
The ZZ plant doesn't prefer absolutely dry spaces.
Living in a place where the conditions become a little dry most of the time can make things difficult for the plant. So, try to keep it in a room where the humidity levels are slightly more than in other rooms in your home.
The kitchens and bathrooms generally have more humidity than other rooms, so you may experiment by keeping the plant in such rooms. But yes, observe the plant's growth and see how it's doing in these conditions.
Note: If the plant is already facing a fungus issue, you shouldn't place it in bathrooms. The high humidity in the room will increase the growth of fungus on the plant.
6. Prune The Dead Brown Stems
It would help if you removed the dead brown stems from the plant. The dead stems won't come back to life magically.
Moreover, these stems will also have fungus, so do not throw them in the compost bin. Discard them entirely and clean the scissors with some soap after completing this task.
7. Do Not Fertilize The Plant For A Few Months
As I mentioned in the guide, the ZZ plant doesn't require much fertilizer. It is meant for harsh and arid conditions.
So, it will thrive for a long duration, no matter how many nutrients are available in the soil. This plant stores its resources in the root bulb. Hence, you can avoid fertilizing the plant frequently.
8. Transplant The ZZ Plant
If nothing works, this is the best thing you can do to revive your plant.
Of course, you can't fix the brown stems entirely with this method, but the new stems will surely have a green color. The new ZZ stems will look much better when they come up from the new growing medium. So, that's the main advantage of moving such a plant to entirely different soil and growing space.
Furthermore, the new environment will encourage the plant to produce new shoots in the coming weeks or months. Once these shoots pop up from the soil, you can keep them growing in the same pot or separate them from the mother plant. And that's really up to you.
If you feel the main plant is still going through the same situation, you should try propagating the new shoots in different pots.
It means the plant is affected by some possible conditions, including fungus attack, overwatering, sun exposure, and high humidity. These things can cause many issues in the plant, and the brown stem problem is just one of them.
The ZZ plant stems turn black due to the black fungus or overwatering. It's an advanced stage of this issue, which needs immediate attention from plant parents.
The plant can turn yellow and brown for various reasons. Some of these reasons include - overwatering, underwatering, overfertilization, lack of nutrients in the soil, fungus or bacteria attack, and transplant shock.
You will need to assess the condition of your plant thoroughly to see what exactly is causing such an issue in the plant.
Yes, it can be reversed, but it depends on the damage to the stem and roots. If the stem is mushy, you won't be able to revive it fully.
Yes, the thriving ZZ plant will grow many stems in its lifetime. If it's undergoing any stress or issues, you won't see any new growth for a long time. It's a slow-growing plant, so do not expect such growth during such a period.
Over To You
I hope you found this guide helpful. You may find fixing this issue on your plant challenging, but the above suggestions should help during this process. So, do try them out!
If you have any queries about this topic, leave a comment below. If you liked this guide, share it with your friends and family.