Why Are My ZZ Plant Leaves Turning Brown | How To Fix It

The leaves of a healthy ZZ plant, or Zamioculcas zamiifolia, are so green and glossy that they can easily be mistaken for fake greenery. Rest assured, however, that this low-maintenance houseplant is 100% the real deal.

With all of that said, your ZZ plant will quickly give away its living status if its foliage is brown and damaged rather than a waxy shade of green. 

In this article, I break down some of the most likely explanations for ZZ plant leaves turning brown. I also offer advice for preventing and treating brown foliage based on my own personal experience.

Why Does My ZZ Plant Have Brown Leaves?

When any plant leaf turns brown, it means that the tissue is either dead or well on its way to dying off. 

This process is relatively natural for deciduous shrubs and trees that lose their leaves each fall. For a tropical evergreen like the ZZ plant, however, the leaves should remain healthy and green all year long. 

If your ZZ plant suddenly presents with brown foliage and/or other unusual symptoms, it’s a clear sign that you need to re-evaluate the plant’s health and growing environment for potential problems. 

7 Causes Of Brown Leaves On ZZ Plant

There are a number of common reasons your ZZ plant might develop brown leaves. Diagnosing and treating the problem as quickly as possible is important regardless of the root cause.

As you read through this list, I encourage you to think about your ZZ plant’s individual symptoms — including those that might seem unrelated to its discolored leaves — to help narrow down what might be ailing it.

1. Underwatering

Chronically dry soil is a very common cause of ZZ plant leaves turning brown. Other symptoms you might notice include limp or drooping foliage and wrinkled stem tissue.

ZZ plants should ideally be watered when the soil is about 50% dry. Check with a finger pressed a few inches deep to determine if your plant’s potting soil is in need of water.

Note that an established ZZ plant might need more frequent watering than usual if the weather is hotter or drier than average.

2. Overwatering

ZZ plants do not tolerate waterlogged soil. If yours is left to sit in damp soil, you might notice yellowing or browning starting at the tips of the leaves. The leaves may also feel unusually soft when gently squeezed.

New growth shows a yellowing or pale green color and the tips of the plant soften and turn brown as you can see in the image below. In this case, I had to re-pot the plant in fresh dry potting soil and prune off the entire stem of growth down to the base.

Good soil drainage is the first step to preventing symptoms of overwatering. Excess water needs somewhere to go, or else it will sit inside the container and smother your ZZ plant’s roots.

In addition to proper drainage, be sure to follow my recommendation above of only watering when the soil is partially dried out.

zz plant brown tips on young leaves
ZZ plant showing signs of overwatering

3. Low Humidity

While ZZ plants typically enjoy average household humidity levels, overly dry air can take a toll. If the air around your ZZ plant is extremely dry, moisture will be pulled from the foliage. This can cause browning and dryness that starts along the edges of the leaves.

You can supplement the air near your ZZ plant with a standard humidifier or a DIY pebble tray. I generally don’t recommend misting as a way to increase ambient humidity around houseplants but some gardeners claim to see great results.

4. Harsh Sunlight

One of the reasons these houseplants fare so well indoors is their ability to adapt to low-light conditions. Meanwhile, ZZ plants that receive too much direct sunlight often develop burnt leaves.

Acute sunburn can present as brown patches on exposed leaves. You might also notice that excess sunlight makes your ZZ plant more susceptible to drying out due to low humidity or underwatering.

ZZ plants should receive at least 6 hours of bright, indirect sunlight daily for optimal health. 

5. Temperature Shock

Houseplants that experience extreme or rapidly fluctuating temperatures often go into shock. Exposure to something like a radiator or drafty window can confuse your ZZ plant and trigger leaf dieback.

According to the University of Florida, ZZ plants prefer warm temperatures between 65 and 90°F. They may be damaged by temperatures below 50°F.

6. Water Quality

ZZ plants are more sensitive to chemicals found in treated tap water than some other species. If your area’s water contains a lot of fluorides, chlorine, or similar compounds, you might notice the leaves of your ZZ plant start to turn brown in response.

The simplest solution is to use bottled or heavily filtered water. For a cheaper alternative, use rainwater or leave your tap water to sit out for at least 24 hours before using it. This waiting period allows most of the chemicals inside to evaporate.

7. Root Rot

Root rot is a soilborne disease that — as the name implies — eats away at the infected plant’s root system until it can no longer supply water, oxygen, and nutrients. Nearly all cases of root rot are triggered by overly damp soil conditions.

The tricky thing about root rot is that the disease can go undetected for a long time before symptoms like brown leaves appear above the soil’s surface.

Treating root rot is almost entirely about prevention. Ensure your ZZ plant has well-draining soil and a container that isn’t too deep for the plant’s size. The container should also have ample drainage holes in the bottom.

The pathogens that cause root rot are sometimes spread through contaminated soil or tools. I strongly suggest using fresh potting soil and routinely sanitizing your containers and tools to prevent the accidental spread of this disease.

How To Remove Brown ZZ Plant Foliage

Pruning isn’t a normal part of the ZZ plant’s care routine. If your plant has a few brown or yellow leaves, however, this is a quick and easy way to remove the damage.

Always use clean, sharp pruning shears or scissors. I also recommend sanitizing the blades with rubbing alcohol when you’re finished.

Since leaves that are brown or yellow won’t return to green, you can feel free to cut away any discolored foliage. Prioritize leaves that are predominantly brown, being careful to remove no more than one-third of the plant’s total foliage.

You may like to read this article on How To Propagate ZZ Plant | Zamioculcas Zamiifolia

FAQs ZZ Plant Turning Brown

Should I Cut Dead Leaves Off Of ZZ Plant?

Yes, you can cut dead or damaged leaves off of your ZZ plant to clean up its appearance and redirect energy into producing new, healthy growth. Prune damaged leaves using a pair of clean, sharp gardening shears or scissors to prevent the spread of disease. 

Citations

Website | + posts

Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.