Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.
What is a ZZ Plant?
The ZZ plant (Zamioculcas zamiifolia) is native to tropical regions in Africa. It was “discovered” by Europeans in 1829, but didn’t become popular as a houseplant until the late 1990’s when Dutch nurseries began growing it for sale.
ZZ plant is also known as aroid palm because it is a member of the Arum family which is also called the Aroid family. Aroid plants all grow from rhizomes or tubers and their flowers grow on a spadix which is surrounded by a spathe.
ZZ plant is perennial in zones 10 – 12. In colder regions, it is grown as a houseplant. It has a reputation as a good plant for people who are unable to grow houseplants because it can grow in almost no light and can go months without watering.
The plants grow from a thick rhizome which holds water to get it through dry periods in its native environment. That is why if you forget to water your plant, it won’t die. It will use the water stored in its rhizome to keep it going until you remember to water it.
ZZ plants grow 3 – 4 feet tall. The stems of the plant which have small leaves along them are not really stems at all. They are the leaves of the plant. The plants have no stems. Each leaf (stem plus leaves) grows directly from the rhizome. The leaves are shiny. Like other leaves, they do become dusty over time but resist the temptation to use a leaf shine product to make them shine again. These products will clog the pores of the leaves which will prevent them from respiring. Use plain old water to clean your leaves and bring them back to their shiny state.
You can’t prune your plants to make them bushier. If you cut one of the leaves anywhere along its stem, it won’t grow new bushier stems. Instead, if you want more leaves, cut the “stem” at the bottom where it is growing from the rhizome. This will signal the rhizome to grow more leaves.
The leaves along the stem are also another adaption to the plant’s dry environment. They are thick and fleshy and hold water like the rhizome. They live up to 6 months. One way you can tell that you are overdue to water your ZZ plant is if the leaves start to fall off. This means that they have exhausted all of their stored water so the plant is getting rid of them to help conserve water in the rhizome. Don’t worry. Just start watering your plant again and it will start growing new leaves to replace the ones that died and fell off.
The ZZ plant blooms, but the flowers can be difficult to see because they are hidden at the base of the leaves. The spathe which surrounds the flowers is often mistaken for a flower. The actual flowers grow on a spadix inside the spathe. The spathe is a light yellow or cream color. Bloom time is from mid-summer to early fall.
How to Grow a ZZ Plant
ZZ plants do best in bright indirect light, whether grown indoors or outdoors. Avoid direct sunlight. This will scorch the leaves. They will also thrive under the fluorescent lights found in office buildings.
Well-drained soil is a must. If the soil doesn’t drain, the rhizome will rot and the plant will die. Regular potting soil works fine. You can also add sand or perlite to provide extra drainage. Plant your rhizome in a pot that is 1/3 as wide as your rhizome. If you use a pot that is too big, it will hold too much soil which will hold too much water and your rhizome will rot.
Don’t give in to the temptation to repot your ZZ plant into a larger pot until it has completely filled its current container. Wait until the rhizome is actually touching the side of the pot. Then transplant it into a larger container that is 1/3 as wide as the rhizome.
One way that gardeners kill this indestructible plant is by overwatering it. Too much water will cause the rhizome to rot. You only need to water your ZZ plant every 2 – 3 weeks. A good rule of thumb is to water it only when the top 3 inches of soil is dry.
Like most drought tolerant plants, ZZ plants don’t need fertilizing. They thrive in poor soil. If you wish to fertilize your plant, use a fertilizer that is specifically formulated for houseplants and dilute it to half strength. Apply it no more than once or twice during the growing season.
How to Divide a ZZ Plant
When you purchase a ZZ plant, you will be getting multiple rhizomes in the container. This is because the plants grow faster when there is more than one rhizome growing together. To divide your plant, when you are repotting it, simply break the rhizomes apart and repot them in separate pots making sure that you have more than one rhizome in each pot.
How to Grow a ZZ Plant From a Leaf Cutting
You can propagate your ZZ plant from a leaf cutting as long as you have a lot of time and patience. It can take 6 months to a year before the new rhizome forms.
You can take a cutting anywhere on a leaf a long as it has at least 2 leaflets attached. Insert the stem into a container of moist, well-drained soil and then put the container and cutting in a plastic bag to create a humid environment. Place it in a window with indirect light. Check the soil periodically to make sure that it remains moist. Not wet, just moist. The leaf may die. That’s okay. At that point a new rhizome should be growing in the soil. It will take anywhere from 6 months to a year before the new rhizome is large enough to start growing its own foliage.
© 2020 Caren White