How Often to Water a ZZ Plant for Lush Foliage Year-Round

The ZZ plant (Zamioculcas zamiifolia) is native to the dry grasslands and forests in Eastern Africa, making it especially drought-tolerant. It is an especially popular houseplant because of its ability to flourish with minimal care, thriving in areas with low light and with very little water. That said, like any living thing, ZZ plants require some moisture to survive. To keep your plant healthy and maintain its glossy, green leaves, we spoke to gardening experts who shared just how often a ZZ plant needs water.

When to Water a ZZ Plant

ZZ plants are notoriously drought-tolerant, with some plant owners getting away with watering them only once a month. "But tolerating drought isn’t the same thing as liking drought, so you can water more regularly if you want your ZZ plant to grow faster," says Justin Hancock, horticulturist at Costa Farms. He recommends watering when the top half or so of the potting mix feels dry to the touch to avoid over or underwatering your plant.

Factors to Consider

How often you water your ZZ plant depends on several factors, including temperature, humidity, sun exposure, container size, and soil quality.

Soil

The faster your potting mix drains, the quicker it will dry out and the more often you will need to water your ZZ plant. "A regular potting mix, for example, will probably require fewer waterings than if you used a potting mix designed for orchids or cacti and succulents, since they’re designed to dry out faster," says Hancock.

Sun Exposure

Sun exposure has the greatest impact on how often your ZZ plant needs a drink. "Light produces all the energy your plant needs to grow, so the more light it gets, the faster it grows and the more water it drinks to support that growth," explains Hancock. "With less light, your plant will grow more slowly, so it uses less water from the potting mix."

Container Size

Container size also plays a part in your ZZ plant's watering needs. "Because potting mix acts like a sponge, the bigger the pot, the more moisture it holds and the less frequent watering is needed," says Hancock. "But there’s a fine line. In a pot that’s too big, you need to be really careful about watering because if your ZZ plant doesn’t absorb enough moisture fast enough, the roots could start to suffocate, and your plant suffers from overwatering."

Temperature and Humidity

The temperature and humidity in your home may dictate how often you need to water a ZZ plant. These plants grow more quickly in warmer weather, and the faster they grow, the more water they require. Additionally, moisture evaporates from the soil faster in dryer conditions than humid ones, so you may find your plant dries out more quickly in arid versus humid environments.

"That said, factors like light and temperature have more impact than humidity on water needs," says Hancock. "If you heat your home with a furnace in winter and it drives down humidity to desert-dry levels, your ZZ plant may not need more water than it did in summer because the lower light levels are slowing the plant’s growth more than the evaporation rate is sucking moisture out."

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Signs of Overwatering

An overwatered ZZ plant will develop soft, yellow leaves that fall off the plant, says Lisa Eldred Steinkopf, founder of The Houseplant Guru. If the overwatering continues, Hancock says the roots will become soft, mushy, and discolored due to rot. If this is the case, repot your ZZ plant in a container with fresh potting soil.

Signs of Underwatering

The signs of underwatering often present similarly to those of overwatering, but the main difference is that the leaves will feel crispy, rather than pliable, says Steinkopf. "These are naturally arching plants, but when they are dry, they will droop more," she adds.

That said, underwatering is better than overwatering, and it's possible to revive a thirsty plant. "ZZ plants are so drought-tolerant that they can lose all their leaves and still potentially bounce back because of their potato-like rhizomes," says Hancock. "If you can still see or feel the rhizomes in the potting mix, give it a bright spot and resume watering—it may start to put out new leaves again."