Excessive watering is virtually the only thing that can be considered a genuine threat to the resilient ZZ Plant (Zamioculcas zamiifolia).
Strong light? It’s devoured. Is there a lack of sunlight? There are no hassles. Is it barren soil or a heatwave? It won’t be a problem at all.
However, if you over-water these tough champions, they will perish as any other plant would.
Overwatering the ZZ plant causes yellow leaves, soft roots, and mushy stems. Allow the soil to dry out and replace any soggy soil if necessary. Inspect the root system and repot the plant in a clean medium container if you find any signs of decay. Root rot is a possibility.
Signs of Over-watered ZZ Plant
Here’s what to look for and how to treat an overwatered ZZ Plant.
Leaves Turning Yellow
Yellow leaves are the first and most obvious sign of an overwatered ZZ Plant.
Because the plant is known for its bright, glossy foliage, it’s easy to spot the change in an appearance here.
The ZZ Plant’s roots require air pockets in the soil to thrive. Unfortunately, water seeps into the air pockets, and the roots begin to suffocate and eventually rot.
Constantly wet conditions aid in the growth of the fungus, which infects the roots and causes the disease root rot.
They can no longer supply leaves with water or nutrients from the soil, as they have died out. Consequently, the leaves turn yellow.
Mushy Brown Stalks
The brown, soft stalks are different from the springy, strong stalks that a healthy plant usually has.
Instead, the stems emerge from the rhizome, a shared fleshy root that acts as water and nutrients reservoirs.
Rhizomes in good health will produce branches that are solid and healthy.
But the stems of a ZZ Plant that gets too much water are often soft and corky.
This is because it takes on too much water, allowing pathogens in the soil to take advantage of the decaying roots and wreak havoc on it.
So first, they will take the ZZ Plant’s roots from the rhizome to the stems. Then, as the stems rot, they turn brown and soft.
Rotting Roots And Smelly Soil
Finally, be on the lookout for stagnant water and smelly soil. If the smell is fishy or strongly reminiscent of rotten eggs, your roots rot in the pot.
Root rot is caused by too much watering, but the real culprits are fungal pathogens that live in the soil.
Fungi come in a wide variety of species, and many of them enjoy munching on decomposing roots.
However, no matter what species is involved, the result is always the same: rotting roots and smelly soils.
Drooping Leaves
No matter how much water you add to the pot, the plant cannot draw water from the soil without solid roots.
As a result, the stems start to lose their turgor, which is the water pressure within the branch and contributes to keeping the stem upright and active.
They quickly lose their vigor and become sad and wilted.
ZZ Plant Leaves Soft
Alternatively, if the roots are still working, that extra water will make its way to the leaves. They swell up and become soggy and soft.
Some fungi live in the soil that loves to colonize the deliciously moist tissue when they begin to rot.
If the leaves are wet and soggy, they’ll soon turn yellow and brown.
The outer layer of the leaf may flake off, revealing the diseased and wet tissue inside.
The ZZ Plant Falling Over
The rhizome of the ZZ Plant serves as much more than just a reservoir for water and nutrients.
It is also the plant’s main point of support. The ZZ Plant stays stable in the ground because it has a robust rhizome. The rhizome suffers and begins to rot if you over-water it.
In addition, the ZZ Plant becomes unbalanced and unsteady in its container due to it losing its footing.
This is especially true if the plant has been overwatered for a long time, which will hurt the rhizome and all of the other roots.
Assess the Damage to Decide the Next Steps
Find out just how bad things are with your ZZ Plant by closely looking at it.
Treatment can be as simple as moving the plant or as complicated as repotting.
The condition of the soil is crucial. If it’s wet but only smells like compost or dirt, you may be able to dry out your ZZ Plant with no harm done.
However, if the growing medium smells terrible, you’ll need to take a more drastic approach.
Also, watch out for mold or mildew that you can see on the soil’s surface.
How to save over-watered ZZ Plant
[1] Move the ZZ Plant to a Sunny Spot
For a mildly over-watered ZZ plant, you can start by moving it to a sunnier spot.
They can tolerate a surprising amount of light, and the more light, the quicker your medium will dry.
Intense light inspires the ZZ Plant to photosynthesize at a faster rate.
This process turns sunlight, water, and oxygen from the air into the simple sugars the ZZ uses for all its biological functions.
The more it can photosynthesize, the more water it will draw from the growing medium.
As a bonus, the extra bit of light will give it the energy to repair any damage caused by the over-watering.
So it’s a good tactic for a plant that’s only a little over-watered.
[2] Place The Zz Plant Near A Window
The soil will dry faster if you place the ZZ Plant closer to a window.
Not only will the additional light assist the plant in drawing moisture from the soil, as I have previously explained.
But windows that are opened and lots of fresh air will also help dry the area through evaporation. It’s like drying socks in the wind: good airflow will speed up drying.
[3] Change To A Fast-Draining Soil After Drying Out The Plant
Look closely at the growing medium once it has had a chance to dry out.
If the medium isn’t well mixed, even a tiny amount of water can build up and become a problem.
Is the soil heavy and loamy? Does water take a long time to drain to the bottom?
If this is the case, it’s time to replace it with something more appropriate.
The medium that smells bad or is moldy should also be thrown out.
I mix my soil by combining one part potting soil, one part orchid bark, one part perlite, and one part peat moss or coco coir with a few handfuls of coarse sand.
This blend has good flow and a lot of texture to keep those critical air pockets in place.
Peat or coco coir retains moisture, but it releases nutrients that help boost fertility as it decomposes. It’s a fantastic choice for your ZZ Plant.
[4] Choose a Pot with Good Drainage
Additionally, a change in medium provides an excellent opportunity for pot improvement.
Free-draining soils are useless if water cannot escape from the container!
Make sure your container has at least three drainage holes and that they are evenly spaced around the bottom of the container.
A porous material, such as terracotta, unglazed ceramic, or concrete, is another option that I would recommend.
Materials with a porous structure are better at wicking away moisture from a medium and assisting it in drying out.
If you have a habit of being too generous with the watering can, this could be a real game-changer.
[5] Prune Dead And Diseased Roots And Leaves
Repotting is a good time to inspect the roots and remove any damage or dying.
Healthy roots are light in color, ranging from white to cream. They’ll be tough and fibrous but not brittle.
Dying or dead roots may be dark brown, black, or even orange.
The decay is causing the color change, and they will need to be cut away. You can use sterile shears or scissors to cut them off.
Take the time to remove any dying or dead leaves. Because they are not contributing to the plant’s recovery, it is safe to remove them.
[6] Treat The Roots with A Fungicide
By applying a fungicide to the plant’s roots, you can revive an ailing ZZ Plant and help it recover more quickly.
For mild cases, you can sprinkle cinnamon powder on the roots.
It contains antifungal compounds and stimulants of root growth, making cinnamon powder a potent antifungal remedy. Incredibly, it’s an all-natural alternative that works.
If the infection is particularly severe, it may be in your best interest to resort to more drastic measures and apply a copper-based fungicide (Check out the prices on Amazon here).
They’re dangerous chemicals, so read all the instructions and wear proper safety gear.
[7] Adjust The Watering Schedule
Once you’ve let the ZZ Plant dry out after giving it too much water, it’s essential to keep it healthy by only giving it water when it needs it.
You’ll need more water in the summer and less in the winter, but you should let it dry out between waterings.
Additionally, larger plants have a more critical requirement for water, whereas smaller plants require less.
A plant in a brightly lit area will require more moisture than one in a shady corner.
It may appear not very careful, but ZZ Plants do not require much water.
No matter how dry the conditions are, their resilient rhizomes ensure that they can continue to thrive. Allow the medium to dry before rewatering completely.
It may seem extreme, but because the ZZ Plant has evolved to thrive in arid conditions, it cannot tolerate wetting its feet.
When to Water Your ZZ Plant
When watering my ZZ Plants, I use a disposable chopstick to inspect the soil before applying any water. Then, I put it in the medium and wiggle it to the bottom.
It’s time to water if it comes out clean and dry. I put the watering can away if the tip is wet or the chopstick is wet. Simple but highly effective!
If you want to be more precise, you could also use a small, hand-held moisture meter. (Check out the prices on Amazon here)
For the more scientifically minded gardener, this tool uses a mild electric current to measure water levels in the soil.
Treating Severe Root Rot From Over-Watering
Severe root rot in ZZ Plants needs treatment right away. The steps are simple, but they could be lifesaving for your ZZ Plant.
You will need:
- Sterile shears or scissors
- Clean growing medium
- New, clean pot
- Fungicide (cinnamon powder is ideal)
- Lots of clean water
- Large plastic tub or basin
- Clean towel or tarpaulin
Remove Infected soil
Start by pulling out the roots from the wet, diseased soil.
Fill your tub or basin with a lot of clean water. Then, take your ZZ Plant out of its pot and gently wash its roots in the tub.
I find that most of the mess can be cleaned up by just swishing the plant around in the water.
This soil cannot be recycled. Instead, pour the water down a drain, and throw the dirt away with your regular trash.
Remove Damaged Root Tissue
After removing the soil clinging to the plant’s roots, you can remove the plant from the container and examine the roots themselves.
Place the ZZ plant on the towel, and with close attention, investigate the entirety of its root system.
You will need to remove any dark brown, black, or orange roots.
This includes removing any soft parts of the rhizome, which should be done with extreme caution.
You can’t put these dead roots in the compost. Instead, just throw them in the trash, and sterilize any tools used to cut infected roots to prevent the spread of disease.
Apply Fungicide
Dust the trimmed roots with cinnamon powder or rinse with a commercial fungicide.
If you choose to use a chemical treatment, follow the directions and wear the proper safety gear.
Provide New Medium
Fill a new, clean pot with fresh potting soil. The best ingredients for a good mix are one part of orchid bark, perlite, one potting soil, and one portion of coco coir or peat.
Make it wet enough to stick together but is not damp to the touch.
You should also make sure that your pot is clean and sterile.
There isn’t much point in trying to heal a sick plant if you’re going to put it back into the same infected container!
Place the ZZ Plant in its new pot with caution, making sure not to disturb the roots, and then carefully fill in the space around them.
Prune Sick Branches And Excess Growth
You should look for rotting stalks if you’ve had to remove any diseased root materials from your ZZ Plant.
You will likely find a few branches that are beginning to become brittle at the base; you should remove these branches. They are dying and will not survive.
Additionally, if you’ve had to cut back the plant’s roots, it’s good to trim back the plant’s body.
Fewer branches place less stress on the roots, increasing the likelihood that they will make a full recovery.
Water Sparingly
After you have given the ZZ Plant one thorough watering and allowed it to drain, put it back in its original location.
Before you water it again, make sure that it has had ample time to dry out completely.
Before the roots are watered once more, this will give them some time to recover from the surgery they recently underwent.
In addition to this, it will provide the fungicide time to perform its function before subsequent watering washes it away from the soil.
Consider Propagation
- When you prune away dead roots, you may quickly realize that the whole system is lost. It’s time to propagate if the lot is blackened and rotting.
- The easiest way is to cut off a healthy branch and put it in a water container. Even a single leaf can be used to start a new plant, but a branch tip with two or three leaves is the ideal starting point for propagation.
- They require consistent bright, indirect light and prefer temperatures around 80°F (26°C). By “green-housing” the cutting in a clear plastic bag or tub, you can keep it warm and help that important rhizome grow.
- If you keep it warm and give it plenty of light, it can take as little as four to six weeks for a stem cutting with a few leaves to grow a rhizome and roots. A single leaf takes a lot longer, and some growers say they are ready to plant after about nine months.
- You can start a new ZZ Plant once it has developed at least two inches of roots and a rhizome after it appears.
Ways to Prevent Over-watering ZZ Plant
ZZ plants have evolved to thrive in dry, hot environments. Most of us believe that dry soil is the most difficult for plants to tolerate.
We don’t like being hot and dry, so it’s easy to overlook those desert specialists as the ZZ Plant does.
To protect the ZZ from over-watering:
- Before watering, use a chopstick or a moisture meter to check the growing medium.
- Make use of a free-draining medium.
- Make sure that the pot has at least three drainage holes.
- Before watering, consider the seasons and the growing conditions.