When and How to Water ZZ Plants

ZZ plants, also known as Zanzibar gem or Zamioculcas zamiifolia, are a popular choice for indoor gardeners offering a host of beneficial properties and symbolic value. Not only do these attractive plants require little maintenance and tolerate low light exposure, but they’re also known for their ability to clean volatile pollutants from indoor air. Native to eastern Africa, ZZ plants thrive in dry conditions, thanks to a highly effective rhizome root system that processes water efficiently. Read on to learn how to water your ZZ plants.

When and How to Water ZZ Plants – The Essentials

ZZ plants typically require watering twice per month in spring and summer and once per month during the winter or in low light exposures. ZZ plants are semi-succulents that thrive in well-draining soil. They like to dry out completely between waterings. Before watering, check the plant’s moisture at the root level using a probe. 

The Role of Water in Plant Health and Development

As with all other plant life, water is essential to ZZ plants’ life and health. This dependence on water starts with seeds; without fresh water, seeds can’t germinate. Water delivers the vital nutrients plants need, such as minerals and organic nutrients. Plants retain the water they need to grow and hold their shape and form.

Plants also depend on water for photosynthesis. This process, by which plants take up water through the roots and transpire moisture back into the atmosphere through their foliage, is key to our planet’s water and carbon cycles.

When to Water ZZ Plants

ZZ plants prefer soil on the dry side, mimicking the semi-arid conditions in their native habitat. Water only when the soil feels completely dry, including at the root level. Use a moisture probe to ensure there’s no water around the roots. Be particularly cautious with recently propagated ZZ plants.

In the summer, water only when the soil has dried out completely, or about twice per month. During the winter and in low light conditions, plants usually need watering about one time each month.

Your ZZ plant only needs watering when the soil is completely dry. Signs you need to water your ZZ plant include:

• Shriveled, brown, or dry leaf tips
• Leaves dropping one at a time
• Wrinkled or shriveled petioles (stems that grow off the rhizome or rootball)

How to Check When to Water

Before watering, use a moisture meter to ensure roots aren’t wet. You can also stick a wooden chopstick down into the soil; if it comes back dry, it may be time to water.

You may also pick up your plant (including the pot). If it feels heavy, there’s probably still enough moisture in the soil, and you don’t need to water. If the pot feels light, it may be time to water.

Water about twice per month in the summer, but only when the soil has dried out completely. During the winter and when grown in low light conditions, plants may need watering only once per month. 

If your ZZ plant is exposed to bright light, it may need more frequent watering. Generally, ZZ plants that are grown in low light conditions need less water.

How to Water ZZ Plants

Good watering isn’t just about how much, or how often, you provide water. It’s also about drainage, and in the case of ZZ plants, excellent drainage is vital. 

ZZ plants grow best in drier conditions. That means they don’t like wet feet; in fact, too much water leads to rot root and poor plant health.

Use a container that has good drainage holes in the bottom. Choose sandy, loose soil that provides proper aeration and quick drainage. Otherwise, moisture will collect around your ZZ plant’s roots, leading to health problems.

What Type of Water is Best?

Unlike many other houseplants, ZZ plants aren’t bothered by fluoride and other minerals commonly found in tap water. While filtered water is never a bad choice, you can use regular tap water for your ZZ plants.

• Water your ZZ top from the top. A good option is to place the plant in the sink, and pour water gently into the pot until the water flows freely from the bottom of the container.
• Start by pouring a small amount of water and waiting a few minutes for the soil to absorb the moisture. Then slowly add more water until the excess flows from the drainage hole.
• Remove any excess water that disperses into the tray. ZZ plants should never sit in water, as this may lead to root rot.

Signs You Might be Overwatering

Your ZZ plant will let you know if you’re overwatering it. Look for signs such as:

• Yellowing leaves
• Droopy or mushy stems
• Browning stems
• Many leaves drop at once
• Rotting rhizomes (roots)

Signs You Might be Underwatering

Though ZZ plants prefer to be underwatered rather than overwatered, look for these signs that your plant needs a drink:

• Brown or dry leaf tips
• Shriveled foliage
• One leaf dropping at a time
• Shriveled, wrinkled stems

What to Do In Between Watering Cycles

Here’s my go-to checklist for ZZ plants: 

• Dust leaves with a damp cloth or mist and wipe with a cloth.
• Rotate the plant periodically.
• Keep an eye out for yellowing, multiple leaves dropping, and mushy stems (signs of overwatering).
• Watch for brown, crispy leaf tips and singular leaf drop (signs of overwatering). 
• Fertilize your ZZ plant with a light feed in spring and summer also.
• Keep an eye out for common ZZ plant pests and diseases.
• Consider repotting your ZZ plant if it has outgrown its current container.

Wrapping Up

ZZ plants are attractive houseplants that seem to thrive on neglect. With their preference for dry conditions and low light, they’re a perfect plant for rooms with indirect light or even in an office setting. You’ll only need to water your ZZ plant’s a couple of times each month, and these African natives’ will reward you with glossy leaves and vibrant character.

Further reading: How to grow and care for ZZ plants at home.