The ZZ plant (Zamioculcas zamiifolia) is a resilient houseplant known for its glossy, dark green leaves. Native to East Africa, it has adapted to withstand periods of drought, making it an excellent choice for new plant enthusiasts. Its remarkable hardiness comes from its distinctive underground structure, often mistakenly called a “root bulb.”
The ZZ Plant Rhizome Explained
The “root bulb” of a ZZ plant is actually a rhizome, a modified underground stem. These rhizomes are typically thick and tuberous, resembling small potatoes. They store water and nutrients, enabling the ZZ plant to survive extended dry periods and go for weeks without watering. Rhizomes also produce new shoots and roots, contributing to the plant’s growth and spread.
Essential Rhizome Care
Maintaining healthy ZZ plant rhizomes involves mindful watering. Allow the soil to dry out completely between waterings to prevent excessive moisture. Overwatering is a common issue that can cause significant problems.
A well-draining potting mix, such as an all-purpose mix amended with perlite or sand, aids drainage and aeration. Pots with drainage holes are necessary to prevent waterlogging around the rhizomes.
Troubleshooting Rhizome Issues
Despite their resilience, ZZ plant rhizomes can encounter problems, most commonly rot from overwatering. If rhizomes become mushy, dark, or soft, it signals rot. Yellowing leaves can also signal overwatering and rot.
To address this, carefully remove the plant, inspect, and prune away any affected rhizome parts using clean tools. Allow trimmed areas to air-dry and callus before repotting in fresh, well-draining soil.
Conversely, extreme underwatering can cause rhizomes to shrivel or deflate, indicating severe dehydration. A thorough watering may help revive the plant; however, underwatering is generally safer than overwatering.
Propagating with Rhizomes
Propagating ZZ plants through rhizome division is an effective way to create new plants. This division is best performed when repotting a mature plant with multiple stems.
Gently remove the plant from its container and carefully separate the rhizome clumps, ensuring each section has at least one stem and healthy roots. If rhizomes are tightly bound, a clean, sharp knife can cut them apart.
Plant each divided section into its own pot with a well-draining potting mix, burying the rhizome at a similar depth as in the original pot. After planting, allow a few days before initial watering for root injuries to heal.