Zamioculcas zamiifolia, commonly known as the ZZ plant or the Zanzibar Gem, is a popular, low maintenance plant that is almost impossible to kill. But does it like being root bound?
ZZ plants are okay with being slightly root-bound. They are slow growers and don’t like wet feet, so a smaller pot is better than a larger pot that will retain water. However, if the pot gets too crowded, the plant may not get the nutrients it needs, and that’s when it should be repotted.
In this article, I’ll explain in more detail what it means for a plant to be root bound and the common symptoms visible on root-bound ZZ plants. Then I’ll explain when and how you should repot your ZZ plant, so read on!
Root Bound Plants
Being root bound or pot bound refers to a situation when the roots of a plant grow too far and start tangling in on themselves. In a ZZ plant with rhizomes or fleshy tubers underground, the number of rhizomes increases or their size grows larger.
In either case, the plant’s roots end up taking up more space in the pot than the soil and sometimes may grow so far as to bulge out of the pot and block the drainage holes as well.
What Are the Symptoms of a Root Bound Plant?
Rootbound plants typically exhibit a few common symptoms.
The symptoms of a root-bound plant include yellowing, browning, and falling leaves, plants that become ‘leggy,’ and visible fertilizer burn, dehydration, or root rot. These are a result of the increased concentration of minerals in the available soil.
When plants become root bound, the roots take up all the space in the pot, leading the soil to become compacted. This can go either way – the soil may be unable to hold any water, which means all the water runs off without being absorbed by the roots.
Alternately, the roots may be blocking the drainage hole, making the water stagnate inside the pot, causing root rot.
The compacted soil will also lead to uneven distribution and concentration of fertilizer and minerals, which leads to possible fertilizer burn and toxicity of the soil.
Between the compacting of the soil and the concentration of the fertilizer, the plant starts to become ‘leggy.’ This is when the stem extends out awkwardly as the plant tries to photosynthesize more to get the nutrients it needs.
Eventually, root-bound plants die due to a lack of nutrition and water.
Aroids like ZZ plants can survive being slightly root bound because they can survive drought conditions. The plant prefers to be underwatered and slightly starved as the rhizomes are able to sustain the plant for quite a while.
This, when combined with the fact that ZZ plants are slow growers, the plant doesn’t mind being root-bound and won’t need to be repotted regularly.
Eventually, though, the rhizomes will grow in number and size, and the plant will need to be repotted to ensure that it can continue growing well without drying out, rotting away, or starving to death.
Recovering From Being Root Bound
Plants can recover from being root bound fairly easily so long as the situation isn’t too far gone. If most of your ZZ plant has died off, it might be difficult, but even a single stem or rhizome is sufficient to help the plant grow new stems.
To help your root-bound ZZ, you have to remedy the situation by immediately repotting it with the correct techniques. Incorrect repotting can lead to root damage and cause your plant to die off, which would be a real tragedy.
After repotting, you have to give the plant time to recover. Prune away the dead bits of the plant with sharp pruning shears or scissors, ensuring that your cuts are small and neat.
After your repot, wait about a week before you water your ZZ plant. Water thoroughly till water drains out of the pot. Then, let the top two inches of soil dry out between waterings. When in doubt, choose to underwater rather than overwater the ZZ plant.
Repotting Your ZZ Plant
Repotting your ZZ plant is a pretty straightforward process. As long as you take care to repot the plant at the right time, with the right potting mix, and don’t overwater it, your ZZ plant will be just fine.
Below I’ll explain the best time to repot your ZZ plant, how you can gauge if your plant is ready to be repotted, and how you can go about repotting your ZZ plant.
Repotting Season
As with all plants, ZZ plants should not be repotted in the winter.
Plants usually enter a dormant period when it’s cold, and their growth slows down. During this time, plants need less water and fertilizer and will not withstand the shock of being transplanted into a new pot.
The best time to repot your ZZ plants is early spring or summer when the plant is about to enter its growing stage and will need more nutrients to grow.
How Do You Know When To Repot a ZZ Plant?
On average, ZZ plants need to be repotted every two years or whenever the rhizomes grow so large that they start bulging out or distorting the shape of the pot. Even if the plant looks healthy, you might want to consider repotting if there are too many stems crowding the surface of the pot as well.
ZZ plants tend to survive being lightly root bound, but repotting them is a great way of ensuring that the plant continues to thrive. It is also an opportunity to propagate the plant.
How To Repot a ZZ Plant?
To repot your ZZ plant, upturn the pot gently while supporting the stem and let the plant slide out with the potting soil. Either place the ZZ in a new pot one size larger than the previous one or separate the rhizomes and place your plants in different pots filled with good potting soil.
If you’re separating the rhizomes, cut them with clean cuts, removing ones with at least one stem growing on them. If there aren’t any, you can still cut the rhizome and plant it in a new pot because a new plant will grow from the rhizome. Do not saw back and forth when you’re cutting the rhizome. Use a sharp, clean pruning knife or shears.
The best potting mix for the ZZ plant will be a good mix of peat moss and perlite (two or three parts moss to one part perlite) to ensure that the miz drains well and won’t get soggy.
Once you’ve repotted your ZZ plant, don’t water it for about a week. Then, water it thoroughly, letting it dry out between waterings.
The ZZ plant does well without fertilizer, but you can supplement it with a slow-release fertilizer in spring or summer. Be careful not to over-fertilize this plant.
Final Thoughts
The ZZ plant can survive being root bound since it is slow-growing and has a rhizome at its base, which can sustain it for quite a while. When the rhizomes grow out of the pot or start distorting it, you can repot your ZZ plant just before the growing season in spring or summer.
To repot, choose a pot only one size larger than the previous one, or simply separate the rhizomes and plant your ZZ in two different pots to propagate it. Ensure that the potting mix is of good quality and the mix is well-draining.
Sources
- UVM: ZZ plant
- Nitobe: ZZ plant repotting, fertilizing, and watering
- UNC Botanical Garden: Help with ZZ Plant?
- Home & Garden Information Center: Indoor Plants – Transplanting & Repotting
- Garden: Ask a Question forum→Repotting a ZZ Plant
- UBC Botanical Garden: Some advice from the pros on growing Zamioculcas zamiifolia, the “ZZ” plant.