My ZZ Plant Root Bulb Is Exposed – What Does It Mean?

ZZ Plant (say Zee Zee Plant), also known as the Zanzibar Gem, is one of those houseplants you most likely bought as it’s super stylish and almost indestructible. Everyone told you the ZZ plant would be easy to take care of, but suddenly you see your ZZ plant’s root bulb is exposed, and you’re freaking out just a little bit.

There are a few main reasons why your ZZ plant bulb may be exposed: overwatering it, using the wrong watering equipment, the pot being too small, or your plant being root-bound. While ZZ plants are notoriously hardy, an exposed bulb puts them at risk.

Read on to understand why this happens, but also the easy ways in which you can fix this.

Close up of zz plant (or Zanzibar Gem) with bulbs exposed

Do ZZ Plants Have Bulbs?

Plant hobbyists often use the word “bulb” to describe any underground structures of a plant. However, a ZZ plant doesn’t have a bulb or a tuber, but it propagates using rhizomes.

Rhizomes and bulbs perform the same functions: protecting the plant and storing food. However, bulbs and rhizomes are also shaped differently. Bulbs are rounder (like garlic), and rhizomes are flatter and more irregularly shaped.

What Are Rhizomes?

Rhizomes are fleshy structures that consist of modified and swollen stems that develop off an established plant. Rhizomes grow horizontally through the soil close to the surface. Nodes are formed along the length of this horizontal structure, and roots can grow down into the ground from these nodes. Any stems that are formed then grow up to the surface.

Rhizomes are almost like underground batteries. They store energy for the plant in the form of food and water.

Reasons Why Your ZZ Plant Rhizomes (Root Bulbs) May Be Exposed?

There are a couple of reasons your ZZ plant’s rhizomes may be exposed, and it’s crucial to pinpoint precisely why this is the case before trying to solve it.

It’s worth noting that disease won’t cause the rhizomes to be exposed. However, pests may reach your plant if they remain uncovered. If pests don’t get it, they will decay over time, eventually becoming mushy and soft. Before this happens, the color will turn lighter and finally yellow.

Here are the main reasons that might be causing your ZZ plant’s rhizomes to be exposed:

Your plant is root-bound

I often keep my plant in the pot I bought it in for way too long, leading to a plant becoming root-bound.

If your ZZ plant is root-bound (or pot-bound), there isn’t enough space for the roots to grow anymore, and the roots have replaced much of the soil. As the roots continue to spread underneath the ground, it pushes the rhizome up, eventually exposing it.

Image of a person repotting a zz plants that seems root bound

The pot is too small

If you planted your ZZ plant in a too-small pot to start with, there might not be enough soil, and the rhizome can become exposed relatively quickly.

Despite being slow growers, the rhizomes will eventually fill up the entire pot. The larger your plant, the larger the rhizomes will be. As the roots from the rhizomes grow downwards, it eventually pushes up the rhizomes to the surface. Consider repotting your ZZ plan every 2-3 years as a rule of thumb.

You are overwatering your plant

I know this is hard for most of us, but remember this plant can tolerate extreme conditions, so skipping a watering every now and then won’t do any harm. However, overwatering the plant can lead to some of the soil draining from the planter’s holes, eventually leading to an exposed rhizome.

You’re watering your plant Incorrectly

It’s not only about how often you water your plant, but also how you do it that matters. For example, if you use a garden hose, the water’s force will move the topsoil and expose the rhizomes. This can be a slow process, so you might not notice until you see a rhizome sticking out. The same might happen if you water it from the top.

Remember that the soil level also naturally drops in a pot over time. This is due to the organic matter in the soil breaking down, leaving only the ground and larger particles.

What To Do If The Rhizomes (Bulbs) Are Exposed?

If your ZZ plant’s rhizome is exposed, it can cause your plant distress and lead to damage due to the temperature changes, dehydration, and pests. The rhizomes also help the plant to hold water and nutrients, so if they dry out from being above the surface, it will slow your plant’s growth. If the issue persists, your plant may even die. 

The following solutions will help you deal with exposed rhizomes – but remember to pick the solution only after determining the exact cause.

Repot in a bigger container

Pick a middle-sized pot to replant in once you feel the rhizomes are close to the current pot’s walls. However, choosing a pot that’s much too big can lead to root rot.

The rhizome should ideally be planted 1-2 inches below the soil’s surface in the new pot. Take care not to plant the rhizome too deep as this can lead to rot, because the deeper parts of the ground in a pot stay moist for longer.

Divide the bulbs

Your ZZ plant is most likely more than one individual plant that has been grouped together in a single pot. Considering that every stem will normally grow multiple rhizomes, it can quickly become crowded. So even though the plants look great together, you might want to avoid planting too many in the same pot.

Change your watering schedule

These hardy plants store water in the rhizomes, so your plant will forgive you for missing a watering. Only watering as needed will ensure a happy plant and prevent the soil from draining out. It might feel like a small change, but it can significantly impact the ground in the long run.

Change your watering equipment

Sometimes the solution can be as simple as changing how you water your plant. For example, avoid using a garden hose, switch to watering your plant from the bottom (by placing it in a saucer and allowing it to soak up the water), or just add a little bit of water at a time.

Summing Up…

If your ZZ plant root bulb (or rhizome) is exposed, you need to determine why. Once you’ve done that, you can fix the issue using the appropriate solution and ensure the ongoing health of your plant!

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