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If your ZZ Plant shows signs of root rot, like yellowing or wilting, carefully remove it from the pot, rinse and then inspect the roots. Any rotten, smelly, or mushy parts will need to be removed. The remaining rhizome should be planted in a clean, porous pot with new, dry, well-draining soil.
The top killer of the almost indestructible ZZ Plant is root rot. This hidden condition attacks silently and can quickly transform your lush, shiny plant into a yellow, sickly shadow of its former state. Let’s go through how to identify this condition and remedy it before it’s too late.
How To Check ZZ Plant For Root Rot
Root rot can set in quickly, and because it occurs below the soil’s surface, you may not notice it immediately. Usually, ZZ plants plod along steadily and are tolerant of various conditions and even a fair amount of neglect, so any changes in color or rigidity need to be investigated promptly.
If you suddenly notice any symptoms of root rot on your ZZ plant, it is essential that you immediately check the roots and determine if the plant can be saved. Once root rot sets in, it can be fatal as the condition quickly spreads through the entire succulent rhizome root.
To check your ZZ plant for root rot, you need to understand what root rot is and what to look for when examining the exposed roots. As its name suggests, this condition causes healthy plant roots to start rotting, which quickly spreads from affected sections to other healthy parts.
Before removing your plant from its pot to check its roots, examine it carefully for other possible reasons for its deteriorating condition. Rule out all other causes like a possible parasitic infestation or incorrect light before taking the next step.
Above Ground Symptoms of ZZ Plant Root Rot
If you know that you might have overwatered your ZZ plant, and you see any of the following signs above the soil, then you should proceed to check the roots:
- Yellowing of the plant from base upward
- Any mushiness or rotting present on the base of the stem
- Stem weakness or falling over
- Curling leaves or shrunken, wilted looking stems
- Mold or algae may be present around the bottom of the pot
- A dank, rotting odor may be noticeable close to the soil
If your ZZ plant shows any of these signs, it is time to check the roots to confirm your suspicions.
How To Check ZZ Plant Roots For Root Rot
Checking the roots of any houseplant should always be done as gently as possible so that you don’t stress the plant further. Your aim is to uncover the plant’s roots from the soil, examine them, take the necessary action and repot as part of the same procedure.
It is advisable to wear gloves when handling your ZZ Plant as the juices from the plant may cause skin irritation.
Be sure never to remove the plant from the pot by pulling it up by the stems. Tip the pot onto its side and gently slide the contents out without putting pressure on any part of the plant. If your ZZ plant isn’t coming out, slide a long knife around the inside edges of the pot to loosen it.
Once it is out, you need to clean off the roots so that you can inspect them. To do this, you must run them under slightly warm tap water. The water flow should be gentle at all times, and be sure to support the roots during the procedure so that the stems don’t snap off.
When identifying root rot, the main determining factors are its color, how it feels, and how it smells. Healthy ZZ plant roots should feel firm and should not show any signs of slime or sponginess on any part of the root after being rinsed.
If you have ever bought a bag of potatoes and encountered one that has started to rot, that is quite similar to what root rot in your ZZ plant rhizome may feel like. When gently running your fingers over the ZZ root’s surface, you may feel mushy or slimy areas.
The tip of your finger may even be able to penetrate the surface of the root if you probe slightly.
A ZZ plant affected by root rot will also have grey or brown colored roots. A darker color replaces the usual healthy white shade as the roots begin to decompose.
If your plant has advanced root rot, it may not be possible to save the root, and your best option would be to try to propagate a new plant from healthy leaves that are still on the plant. However, if there are still firm, healthy-looking white sections of the root, you may be able to save your ZZ plant if you act quickly.
Causes of ZZ Plant Root Rot
It is not just ZZ plants that can get root rot, and it is a common, often fatal, condition in many types of houseplants.
Root rot can originate from two sources, excess moisture or infected soil. The outcome and treatment of the disease will be the same regardless of the origin, but understanding the enemy makes one better able to prevent reinfection in the future.
Excessive Water As A Cause Of Root Rot
When you think of root rot, one immediately thinks of overwatering as the main culprit. However, watering is not the only way that roots can become sodden. ZZ plant owners are surprised to find that their plant has become a victim of root rot despite their careful watering regime.
Plant roots need oxygen. If the soil around them is constantly soggy and waterlogged, the roots begin to die back. The moment any organic material dies, decomposition sets in, and the rot from one part of the root quickly spreads to healthy parts.
There is nothing wrong with occasionally drenching your ZZ plant, especially if the soil has been allowed to dry out entirely before. The problem arises when the plant stands in damp soil for long periods, and the soil is poorly aerated.
ZZ plants have tubular rhizome roots that store water, so they are equipped to deal with short droughts. Excessive water around the roots can often occur completely unintentionally, even if you maintain a strict watering schedule.
Let’s go through how the soil in your ZZ plant could become waterlogged.
- Overwatering – The leading cause of root rot in ZZ plants is overwatering – often, we tend to love our plants to death. We try so hard to nurture them and don’t want them to dehydrate that we give them too much water. The wet environment becomes a fertile breeding ground for root rot.
Even if you have a fixed watering schedule, make a habit of always feeling the soil with the tip of your finger before watering. Only add more water if it feels dry below the top layer.
- Irregular Drainage Systems – As important as it is for you to give your plant water, it is equally essential that excess water can drain through the pot and away from the roots. The roots will absorb water as it moves through.
Always check the drainage holes on the bottom of the pot are open. Water that becomes trapped in the pot will quickly cause problems. Also, ensure that if the pot stands on a saucer, it is kept empty so the base of your ZZ plant pot isn’t standing in a pool.
If you use a pebble tray to increase the humidity around your ZZ plant, ensure that the pot’s base is raised above the covering of stones.
These attractive features must have big enough pebbles to keep the pot high out of the water. The water must be able to flow through the pot and out into the tray below.
- Excessive Humidity – You may not notice it, especially if your ZZ plant is kept in a very humid area like a bathroom, but beads of moisture from high humidity can build up on the waxy leaves, form droplets, and roll down the stems into the soil below. This slow but constant form of drip irrigation may mean that the soil never fully dries out, leading to root rot.
Another culprit can be too much misting or using a nozzle that isn’t set on a fine spray. Beads of moisture on the leaves can collect roll down the stem and into the soil. This adds to the overall moisture content of the soil.
- Incorrect Soil – ZZ plantsmust be planted in fast-draining soil.The soil must provide plenty of oxygen to the roots, so use fast-draining soil, like a cactus mix. If you use potting soil, add sand or perlite to improve drainage.
- Check the plant’s pot – ZZ plants aren’t usually fussy about what material the pot is made from, and it is much more important to use a quality, well-draining soil mixture than upgrade pots. Terracotta or concrete is better suited to wicking away moisture than plastic, but so long as there are enough drainage holes, even plastic varieties work well.
However, for proper growth and to ensure that excess water can drain through the pot, it is a good idea to check occasionally that the roots have not become pot bound.
Over time the large tuber-like roots can start to fill the bottom of the pot, which can hold moisture back by blocking the drainage holes.
The right-sized pot will allow water to drain over the roots and out through the bottom. There should always be at least an inch between the bottom of the roots and the pot’s base.
Pathogenic Infections As The Cause Of Root Rot
Various types of fungus may be dormant in the soil your ZZ plant is potted in. They are usually entirely harmless and don’t pose any danger to the health of your plant.
Prolonged damp conditions can cause the normally inactive fungi in the soil to become active and proliferate, causing mayhem for your ZZ plant roots. The effect is that the roots begin to rot and the plant starts dying.
Regardless of how the root rot started, once it has begun, the condition is progressive, and even if you correct the soil conditions, if any parts of the infected root remain on the plant, it will continue to spread.
How to Treat ZZ Plant Root Rot
If you have identified root rot in your ZZ plant, it is essential that you immediately take steps to remove the affected sections. The mushy rotten bits need to be discarded, and the remaining healthy parts will need special care during the recovery process.
Let’s go through 8 steps to give your ZZ plant the best chance at survival if it has root rot.
- Prepare your work surface – get everything you need and lay it out. You will need the following:
- Sharp blade or knife
- Sterilizing solution like rubbing alcohol to clean the blade after each cut you make.
- Fresh fast-draining potting soil.
- A new pot – To remove any possibility of the plant being reinfected by the same soil or container, it is best to plant it in fresh, dry soil in a new pot.
- Remove the ZZ plant from its pot and rinse the roots – this needs to be done carefully. The base of the stems may no longer be securely attached, so handle the root base with care while you rinse it in tepid water.
- Inspect the roots of your ZZ plant – Healthy roots should appear white when rinsed. They will have a firm texture. If your plant’s roots are healthy, check that the pot is the correct size, the soil is suitable, and replant it. Look for other possible causes of your ZZ plant’s decline.
- Trim The Damaged Parts of the Root – this is where you will need to perform some surgery on your ZZ plant roots. Any visibly discolored, mushy, or slimy parts will need to be neatly trimmed off, leaving only healthy sections.
Be sure to remove all the soft bits entirely. Cut into the healthy tissue so that you are sure that there is no rot left around the edges of each infected spot. After each incision, clean your blade using the sterilizing solution.
- Repot the ZZ plant – If you are using the same pot, wash it with a bleach solution to eliminate all traces of the fungus. Throw away the soil from the original pot.
Quickly dip the healthy roots sections into a fungicide solution to ensure that no traces of root rot remain. Then use a clean well-draining potting mix and replant your ZZ plant.
- Trim back some leaves – If you have had to remove large portions of the ZZ plant root, it will have a better chance of recovery if there are fewer leaves to support. Using a sterile scissor, snip back one-third to a half of the upper leaves off.
- Water lightly after repotting – Ensure that the drainage holes are open and there is no chance of excess moisture building up in the pot. Do not water again until the soil feels dry to touch.
- Place in ideal conditions – Your ZZ plant must be placed in optimal conditions to give it the best possibility of recovery. Although ZZ plants are known for their resilience and can often cope with less than ideal conditions, while the plant is recovering from root rot, keep it in a warm place where it receives plenty of indirect light.
Aftercare While ZZ Plant Is Recovering From Root Rot
ZZ plants are slow growers even when they are healthy. Although you may be eager to see signs of recovery and want to fertilize or water to encourage it, hold off. In fact, it is best not to fertilize a plant recovering from root rot at all because the solution may burn the vulnerable, exposed sections of the root.
While your ZZ plant is recovering from the dreaded root rot, keep an eye on it, but don’t give it too much attention. The rhizome needs time to build up strength below the soil to push up new, healthy growth. Water sparingly to avoid any recurrence of the condition.
In some cases, root rot is fatal, and no matter what you do, the fungus has set in. In these cases, it is impossible to save the plant. Fortunately, there is a lifeline by way of propagation.
If there are any healthy stems or leaves left on your plant, harvest them and try to get them growing. Note that these methods will take plenty of patience, and in the case of leaf cuttings, it may take up to a year before you notice any growth.
Try to propagate multiple leaves or stem cuttings to increase your chances of success as they won’t all take and won’t use up much space. Several leaves can be placed side by side in the same pot and transferred to their own pots once they have developed roots.
There are two methods to grow new ZZ plants from cuttings if the plant has been wiped out by root rot:
- Leaf cuttings – believe it or not, ZZ plants can form new plants from healthy leaves. It will take time and patience, but it can be highly rewarding to multiple your plant in this way. Leaf cuttings are the preferred propagation method for ZZ plants, even in healthy plants.
To propagate new plants from leaves, gently pull healthy leaves off the stem and allow the end to callus over before inserting them at an angle into well-draining soil. You may not notice any growth but keep in mind that the new plants first shoot roots down into the ground before you see any development on the surface.
- Stem cuttings – Only use stems that have no trace of root rot that may have spread onto the above-ground section of the plant. Cut a healthy stem at the base and leave it out for a few days so the cut section can callus over. Then place only the lower end of the stem into water.
After 2 or 3 months, you may notice small roots developing. Let them get at least 2 inches long before potting the new plant into well-draining soil. Stem cuttings are a less reliable method of propagating than leaf cuttings.
Are ZZ Plants Easy To Care For?
ZZ plants are ideal houseplants for beginners because they are very easy to care for. They maintain their impressive, dark green, prehistoric-looking appearance without much attention. All they need are occasionally watering and to be kept in a position where they will get a good amount of indirect light.
Can I Propagate ZZ Plant In Water?
Stems can occasionally be propagated in water, but this is not a reliable method. ZZ plants are best propagated by planting healthy leaf cuttings directly into fast-draining soil. The roots should never be kept in water as they may quickly develop root rot which would be fatal for the plant.
To propagate, remove healthy leaves from the plant and keep them out for a few hours so a callus forms over the cut areas. Then position the base of the leaves in well-draining soil and keep them in a light, warm place.
Should I Fertilize My ZZ Plant?
ZZ plants are not demanding and can do well without additional fertilizer. However, once or twice a year, you can add a diluted fertilizer during the warm growing months.
Will A ZZ Plant Do Well In A Bathroom?
ZZ plants are an excellent choice to keep in a bathroom. They are very hardy houseplants that maintain their good looks in a variety of conditions. ZZ can cope well with the changes in humidity that occur in a steamy bathroom environment.
Ensure that the ZZ plant pot can drain freely so that any beads of moisture that flow down the stem into the soil drain away.
Root rot from excessive moisture is the main enemy of ZZ plants, but if you keep the drainage open and don’t overwater, the plant will do well in a bathroom.