The ZZ plant, or Zamioculcas zamiifolia, is native to some of the driest places on the African continent. It is a popular houseplant that has beautiful, dark green leaves and can tolerate both drought and low-light conditions. Because it typically only grows to three feet tall at the most, it makes a great indoor and even office plant.
ZZ plants do not like to be rootbound, so even though they do not grow into large plants, you still need to be aware of their need to be repotted periodically to avoid any rootbound issues.
Repotting the plant can also keep it healthy and happy by providing it with fresh soil and the space that the roots need to grow freely.
In this article, we will discuss more about how to repot a ZZ plant, why repotting is important, and when to do it.
If you are thinking about repotting your ZZ plant and want to learn more about the process, just keep reading.
Rootbound ZZ plant
ZZ plants do not like being rootbound because the resultant confined space keeps their roots from being able to grow properly and affects their overall growth.
As the plant matures and grows bigger, it will naturally develop more and bigger roots, causing the soil in the pot to become displaced until the inside of the pot holds more roots than soil. The roots will also start to become tangled in the pot and, due to both entanglement and lack of soil, the plant will be unable to absorb the water and nutrients it needs to survive.
When the root mass is left to become even bigger and more entwined, it will also become difficult for water to drain through the roots, and this could lead to root rot. Root rot happens when the water in the pot is unable to properly drain from the soil or the roots, leaving the plant standing in stagnant water for long periods. Because the roots do not get the chance to dry out completely, they will drown and die. The dead roots will become more susceptible to opportunistic fungi or bacteria, which will then cause the rot to become more aggressive. The rot will travel from the roots to the stems and leaves, until the entire plant is affected.
Another downside to a rootbound plant is dehydration. This happens when the pot contains mostly roots and very little soil. Soil helps to retain water, so if there is no soil, no water is retained and the plant quickly becomes thirsty and dehydrated. Because of the lack of soil, the plant is also deprived of essential nutrients.
If you have not been vigilant of the state of your ZZ plant, you will start to notice signs that it is rootbound, such as the yellowing, browning and wilting of its foliage. If you see any of these signs, try to remember when you last repotted your plant and consider the possibility of it being rootbound.
How can I tell if my ZZ plant needs to be repotted?
For beginner gardeners or plant collectors, spotting a rootbound ZZ plant can be difficult. To make sure the plant really is rootbound, you will need to look at the parts of the plant above the soil as well as those under the soil.
Look at the plant’s leaves. A healthy ZZ plant has waxy, dark green leaves. A rootbound plant will have yellow or brown leaves.
The growth of a rootbound ZZ plant is also slow or even stunted. Look at the soil at the base of the plant. In a rootbound plant, the roots will become visible above the soil because there is no space in the pot. Roots will also start to grow out of the drainage holes at the bottom of the pot, for the same reason.
The plant will look dehydrated, and you will notice that the soil dries out very quickly after watering.
The plant’s pot may even crack because of the massive root ball inside.
Check the plant’s roots by laying the pot down on one side and using an old knife to loosen the soil from the sides of the pot. Once the soil is loose, you can pull the plant out with ease. If, even after loosening the soil from the pot, the plant refuses to budge, you might have to break the pot. Do what you need to so that the entire plant can be removed intact with as little damage to the roots as possible.
Once the entire root mass is exposed, you can examine it closely and determine the severity of the situation.
The plant is only slightly rootbound if the roots have only just started wrapping themselves around the root ball.
The plant is moderately rootbound when there are mats forming around the root ball.
The plant is severely rootbound when the mats around the root ball have become solid and there is very little soil left inside the pot.
A slightly rootbound plant can be returned to the same pot and repotted after another year, but a moderately or severely rootbound plant will need to be repotted in a larger pot.
When is the best time to repot a ZZ plant?
ZZ plants do not grow especially fast, but they are not considered slow growers either. They only need to be repotted every two to three years. If you are providing perfect cultural care for your plant, it will grow faster and will likely need to be repotted a bit more often.
Repotting is best done during early spring to early summer, because this is when the plant is just starting to grow actively. Remember that repotting is a stressful experience for a plant, so you will want it to be at its healthiest when repotting so that it can recover quickly. Avoid repotting the plant during the winter, because it is dormant and will not be able to recover as fast.
What pot and soil is best for ZZ plants?
When repotting a ZZ plant, you will need to replace the old soil with fresh soil that is appropriate for a recovering rootbound plant. Choosing the right size pot is also vital, because this can greatly affect the plant’s growth and health. Measure the old pot and make sure the new pot is two inches larger in diameter than the old one.
It may be tempting to purchase a pot that is more than one size larger than the old pot, but this will actually cause more harm than good. A larger pot means more soil is needed to fill the pot, and more soil means more water is retained around the plant’s roots. As we previously established, when the roots are left to sit in soggy soil for long periods of time, they are more prone to overwatering and root rot.
When choosing the potting medium for your ZZ plant, choose a mix that is able to retain water but also drains excess water effortlessly.
You can make your own potting mix by combining one part regular potting soil, one part perlite, one part succulent soil and some compost.
How to save a rootbound ZZ plant
If you have confirmed that your ZZ plant is indeed rootbound, you can either transfer the plant to a larger pot or you can divide it into several smaller ZZ plants.
One thing you need to be aware of when handling ZZ plants is that they produce calcium oxalate, which is a chemical they use to protect themselves. The calcium oxalate crystals are small and sharp and can cause a painful rash and irritation if you come into contact with them. Adults may not be severely affected by the chemical, but try to keep animals and small children away from the plant as they are at higher risk of being negatively affected.
It is best to wear gloves and a face mask when handling the plant, just to be safe.
How to repot a ZZ plant
Repotting a ZZ plant is one way to resolve its rootbound issue. When the plant is transferred to a bigger pot with new soil, the roots will have more space to grow into and more nutrients at their disposal.
If you have a new pot and fresh potting mix ready, you can proceed with repotting the plant.
The night before, water your plant thoroughly so that the plant is well-hydrated and the soil is loose. This simple step will make the repotting process even smoother.
The next day, take the plant to an area where you can make a mess. Lay the pot to one side and pull the plant out of the pot. If you struggle to get it loose, run an old knife between the soil and the edges of the pot to help loosen it.
Once you have successfully removed the plant, try to remove as much of the old soil from the root mass as you can. Remember to be gentle and cause the least possible damage to the roots.
After cleaning off the old soil, inspect the roots for any brown or black roots in the root mass. Remove these discolored and damaged roots using a sterilized knife or scissors. Also remove any brown or damaged leaves and stems.
Prepare the new pot by filling it to about a third of the way up with the fresh potting mix.
Place the plant in the new pot and fill in the gaps with more soil. Do not pack the soil, as you do not want it to become compact.
Place the plant in a spot where it can get plenty of bright, indirect light, water it, and you are done.
To avoid the plant becoming rootbound again, make sure you always look out for signs that point to this problem.
How to divide a rootbound ZZ plant
Another option to remedy a rootbound ZZ plant is to divide the plant into smaller plants. This saves the plant while also propagating it.
As with repotting, water the plant the night before you plan to divide it.
The next day, lay the plant’s pot on one side and gently slide the plant out of the pot.
To divide the plant, use a sterilized knife. Take note of the root bulbs and make sure each section has at least half a bulb.
Prepare the necessary number of new pots,place each section in a new pot and fill it with soil.
Water all the new plants and place them where they can get bright, indirect light.
After several weeks, the new plants should be displaying new growth.
ZZ plants are drought- and low-light-tolerant plants that do well in most living conditions. Because they seem like such independent plants, it might be easy to forget to keep an eye on when they need repotting.
ZZ plants typically need to be repotted every two to three years, but the only way to know for sure is by checking the plant’s roots. If the roots are starting to grow above the soil or out of the drainage holes at the bottom of the pot, you need to remove the plant from its pot and inspect the roots.
If you are sure that the plant is rootbound, you need to either repot it in a pot one size larger than the old one, using fresh, well-draining soil, or you can divide the plant into several sections and plant each section in its own pot, which is essentially propagating your ZZ plant.
If you are able to repot or divide the plant correctly, you should see new growth in a matter of weeks.
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