My ZZ plant has been doing great and has grown relatively well over the years. However, I recently noticed the bulbs emerging from the soil. After a little research, I discovered this happens often, but you shouldn’t overlook it.
A ZZ plant bulb shouldn’t be exposed because it puts the plant at risk of dehydration, pest attacks, and microbial infections. The bulb will change color when exposed for too long and eventually decay. However, you can temporarily expose the plant bulbs to check for signs of watering problems.
In this article, I’ll discuss the ZZ plant bulb, why it sometimes emerges above the soil, and what you should do to protect the ZZ plant from the effects of this exposure.
How to Plant a ZZ Plant Bulb
ZZ Plants are quite challenging to grow, making them one of the most expensive plants on the market. That’s why it’s crucial to plant them properly.
There are three main ways of planting ZZ plants:
- Propagating leaf cuttings
- Rooting leaflets
- Planting bulbs
Planting the ZZ plant bulb is the easiest and fastest way to grow ZZ plants. You can easily get a bulb from the parent ZZ plant and grow it in another pot.
When you have the bulbs, you can now prepare them for planting. However, you shouldn’t plant the bulbs immediately after subdividing them, especially if you inflicted ‘wounds’ on them by cutting large bulb clusters into smaller bulbs.
Leave the bulbs to sit for a few days to allow them to heal after cutting them. The ZZ bulbs store water and may rot if you cover them with soil immediately. Instead, allow it to lose some water before planting them.
Plant the newly divided bulbs as you would a young plant. The ZZ bulb is the “heart” of the plant. The cuts you make will likely shock the plant, but it will recover within a few months.
Step-by-Step Planting Guide
Here’s how to plant a ZZ bulb:
Prepare the Potting Mix & Pot
First, get a well-draining potting mix. ZZ plant bulbs shouldn’t sit in wet soil for long because they will start to rot. A light and fluffy soil mix rich in perlite is a great choice.
At this point, you should also prepare a pot with drainage holes. Choose a pot that is at least ⅓ bigger than the bulb.
Bury Your Bulb
Bury the bulb about 1-2 inches (2.5-5 cm) under the soil’s surface. If you plant the bulb too deep, it’ll likely rot. It will also delay growth. Additionally, the ZZ plant bulb has roots that need space to grow at the pot’s base.
Ensure the bulb is completely covered because when exposed, it will lose water and grow slowly. The bulb will also be vulnerable to pests and diseases, and for a young plant, this will spell doom for it.
Water your ZZ plant bulb until you see water drain out. Wait until half the soil is dry before watering again. The bulb needs adequate moisture to adapt to the new environment but will drown in too much water.
Provide Adequate Light
Move the pot to a spot where it will get bright indirect light. Avoid direct sunlight as it can dry out the soil and the bulb quickly. If next to a bright window, filter the light by adding light curtains.
How to Subdivide the Bulbs
Since one ZZ plant gets multiple bulbs over time, a subdivision is the best way to get more bulbs for planting. A ZZ plant can survive and grow from a cut bulb, so you need not worry that the division will destroy your plant. Instead, you’ll have more healthy plants to add to your collection.
To subdivide the ZZ plant bulbs, you should:
Plan the Division & Transplant
Plan when to divide and transplant the bulbs. Wait for 2-3 weeks before you remove it from the pot.
This gives the rhizome a chance to utilize the water from the soil. It will also make division and transplanting less messy.
Prepare Your Set-Up & Tools
Move the pot to the sink or bathroom. It will be a messy process, so you need space to comfortably divide the ZZ plant.
You’ll also want to have the necessary tools within reach. Ensure you have the extra planters, scissors, a sharp knife, a blunt blade, and potting soil in the same area. This way, you start and finish the process without moving around to find one thing or another.
ZZ plants release calcium oxalate, which are microscopic crystals found in the sap. The wax-like coating on the leaves seals the sap in the plant, but when transplanting, there is the risk of leaves and stems breaking. The sap can cause skin irritation, so it is best to have protective wear.
Lay It on Its Side
Next, gently lay the ZZ plant on its side. You don’t want it to break during this process.
If you have a thin planter that breaks easier, you can cut it off if you won’t need it again. Otherwise, you can use a blunt blade along the inner brim of the plant to loosen the soil and separate it from the pot.
Separate the Soil & Plant
Wiggle the plant back and forth to get the dirt at the base to separate from the plant. Ensure you do it gently and that you hold it at the base because you don’t want to pull out the stem and separate it from the bulb. The new plant will survive better if the bulb has established stems and leaves.
Assess the Bulb’s Status
Check the state of the bulbs after pulling them out. The ideal situation is to have whole bulbs growing independently. However, this is not always the case, and you may find multiple enjoined bulbs growing as one.
Observe the Stems
Observe the stems and how they grow from the bulbs. These will also guide you on how to cut the bulbs.
The bulbs have a better chance of supporting new growth if it has a stem or more with healthy leaves. A bulb can still produce a healthy stem if it doesn’t have one, but it’s always better to have some growth.
Inspect the Roots
Inspect the roots growing from the bulbs. If you can strategically cut the bulb with the roots on each, the better. However, if some bulbs have none, you need not worry because they will eventually grow.
Take a Bulb Measurement
Each bulb should be at least 2 inches (5 cm) long. These bulbs will have enough space to store water and nutrients, as it supports the plant in the weeks when you don’t need to water the ZZ plant.
Separate the Single Bulbs
Some bulbs may separate easily, while others will need more nudging. These bulbs can be hard to cut through, so avoid using a blunt knife. Use a clean and sharp knife to avoid the risk of causing “wounds” on the bulb, which will slow its recovery and growth after you transplant it.
Cut the Rhizomes Into Individual Plants
Cut the inter-connected rhizomes into smaller, individual plants. Ensure you carefully observe the bulbs to differentiate between the parent and the newer bulbs. This way, when you cut the bulb, each piece will have a piece of the main bulb.
However, if you can’t tell the difference, you can cut the bulbs into equal parts.
Here is a video of how to divide and plant the ZZ plant bulb:
Dealing With Exposed Bulbs in ZZ Plants
The ZZ plant has an interesting root system. It has rhizomes (bulbs) from which the thick stems emerge. The bulbs also have tubers that grow into the soil and absorb and transfer water and nutrients to the bulb for storage.
Ideally, the bulbs should be buried 1-2 inches (2.5-5 cm) in the soil. However, the ZZ plant bulbs sometimes emerge above the soil.
This happens for various reasons:
ZZ plants grow well in loose and well-draining soil. Frequent watering can easily wash away the soil from the top of the bulb and flush some out of the drainage holes. As a result, the soil volume in the pot decreases and gradually exposes the bulbs.
High Water Pressure
ZZ plants that grow outdoors, as is the case in zones 10 – 12, will also have their bulbs exposed when you water them using a garden hose with high water pressure.
ZZ plants don’t need large containers because they like being snug. And since they are slow growers, they can stay in the same container for years. One of the signs that your ZZ plant is ready for repotting is when bulbs start emerging out of the soil.
As the ZZ plant grows, the tubers and bulbs also grow bigger. As the plant becomes rootbound, it displaces the soil, forcing the bulbs above the soil’s surface.
Potential Risks and Problems of Exposing the ZZ Plant Bulb
You don’t have to panic when you notice ZZ plant bulbs above the soil or potting mix. The ZZ plant can survive with exposed bulbs. However, avoid exposing them for too long because the plant will start showing signs of distress.
Plant bulbs generally store moisture and nutrients to feed the plant. However, when they absorb too much water, they become mushy and rot. That’s why ZZ plant bulbs should ideally be close to the soil’s surface because they will take in too much water when buried too deep.
On the other hand, you may also encounter some problems when the bulbs are exposed.
Here are some of them:
- They lose water faster and start to wrinkle and shrivel.
- They change color. The bulbs are naturally dark. However, they become lighter when exposed over a long time, eventually turning yellow.
- Dehydrated bulbs can’t send enough water to the leaves, causing them to turn yellow. The leaves may also change color because the rhizomes and tubers are rotting if the cause of the bulb exposure is overwatering.
- Dehydration can also cause drooping of the stems and leaves.
- Pests and diseases may start attacking the bulbs.
- Slower or stunted growth may occur.
Your ZZ plant is safer having the bulbs underneath a thin layer of soil. When the bulbs are exposed, you need to find out why so that you can fix the problem.
You should keep the room humid as you attempt to find the cause. This will help ensure the bulbs don’t dry out.
Restoring Optimal Conditions with Repotting and Propagation
Your ZZ plant will survive for some time with the bulb exposed. However, this doesn’t mean that this exposure won’t have long-term effects. The bulb starts losing moisture, so it will not feed the plant as it should.
To save the plant and bulb, you should fix the problem:
A 6-inch (15 cm) pot can hold more than 12 rhizomes. Since ZZ plants thrive in a tight pot, you will have no trouble if the bulbs comfortably fit the pot.
However, when the plant starts pushing the bulbs upwards, or if the pot has bulges or roots growing out of the drainage holes, it’s time to get a pot 2-4 inches (5-10 cm) wider.
You can also propagate the ZZ plant by separating the rhizomes. When you have multiple ZZ plant bulbs, you can get more plants by separating the bulbs.
However, ZZ plants have a better chance of survival if you transplant bulbs with at least three healthy stems with leaves. A bulb without stems may survive but with difficulty.
Top up the Soil
You should top up the soil if the bulbs are exposed because of overwatering or soil loss through the drainage holes. Slowly pour water to avoid displacing too much soil. You can also water the plant from the bottom by filling the tray with water and soaking the pot for around thirty minutes.
Line Your Pot’s Base
Lay mesh pads at the pot’s base before adding soil. You can also use coffee filters to avoid flushing out soil every time you water your ZZ plant.
How to Revive Wrinkled ZZ Plant Bulbs
At one point or another, you’ll discover wrinkled ZZ bulbs. This may be due to overwatering, underwatering, too much sunlight, and age. The possibility of reviving the ZZ bulb will depend on the cause and the extent of the damage.
This is how to address a wrinkled bulb:
- Stop watering the ZZ plant for some time.
- Expose the bulb for a short time to allow it to lose water quickly if the cause of the wrinkles is overwatering.
- Move the plant away from a spot with direct sunlight and water it generously.
- Apply fertilizer twice a year to replenish soil nutrients. Spring and fall applications are highly recommended.
- Remove aging ZZ bulbs when repotting. However, only remove those that have come loose. Over time, old, wrinkled bulbs will fall off and decompose.
ZZ Plant Bulbs Should Not Be Intentionally Exposed
The bulbs on the ZZ plant will become exposed for one reason or another. However, some people intentionally move the soil to expose the bulbs. You might even discover sites that recommend intentionally exposing ZZ bulbs.
You can safely expose ZZ plant bulbs to understand what is happening with the plant. However, you should only expose the bulb for a limited time.
Check your ZZ bulb for watering issues using the following guidelines:
- A shriveled bulb is a sign of underwatering
- A firm bulb shows the plant has sufficient water.
- If the bulb is mushy, it is a sign of overwatering.
You can also expose the bulbs to solve issues, such as encouraging them to lose water faster in case of overwatering. However, exposing the bulb for extended periods makes it vulnerable, so you should cover the bulbs after confirming your diagnosis and resolving the problem.
How to Tell if Your ZZ Plant Is Dying
If you follow the right ZZ plant maintenance routine, your ZZ plant will stay healthy for years. However, sometimes it is easy to err, especially when you water your plant too frequently or go for too long without water.
Here are signs that your ZZ plant is dying:
- Soft and falling stems
- The presence of mold and algae on the soil and at the base of the plant
- Smelly soil, signifying dampness
- Gray, black or brown roots; healthy ZZ plant roots are white and crisp
- Leaf discoloration; he leaves will gradually change color to yellow and brown and will start falling off if nothing is done to remedy the problem
- The ZZ plant stalks won’t stand up
- Exposed bulbs that are wrinkled or mushy
Overwatering is the primary cause of death of the ZZ plant. Once the bulb and roots start rotting, they cannot feed the rest of the plant with water and nutrients. This is when you start seeing changes in the leaves and the stem.
If you don’t act quickly, the bulb will be destroyed, and the plant will lose its lifeline. When the bulbs are exposed, you should observe them instead of rushing to cover them.
You need to confirm if they are healthy or showing signs of distress. Your response will either save or destroy your plant.
ZZ plant bulbs sometimes pop out of the soil. This could be due to several reasons, but the aim is to understand what your ZZ plant is trying to tell you. You don’t have to rush to fix the problem because the bulbs can be exposed for a limited period without it harming the plant.
However, it would be best if you got to the root cause to get the right fix. Overwatering, soil loss, and overcrowding are issues that require attention to prevent your ZZ plants from dying.