Zamioculcas zamiifolia, commonly called the ZZ plant, is a very popular houseplant due to it’s low maintenance. Keep your ZZ plant somewhere with medium light, plant in well-draining soil, don’t over water, and it will thrive! While the ZZ plant is low maintenance overall, there are a few factors that could result in your ZZ plant leaves turning yellow.
Yellow leaves are a sign your plant is unhappy. Keep reading to find out why this common problem occurs and how to fix it.
Read the Complete ZZ Plant Care Guide here
1. ZZ Plant Leaves Turning Yellow Due to Over Watering
Over watering ZZ plants is the most common cause of the leaves turning yellow. ZZ plants grow from rhizomes, which are underground plant stems that store starches and water for the plant (this is why ZZ plants are so drought-tolerant).
Too much water leads to rhizome rot. This means the plant’s roots are not functioning the way they should, so the plant is unable to receive the water and nutrients it needs.
Additional signs of over watering include:
- A lot of leaves are yellowing
- The stalks are turning brown and mushy
- Leaves easily falling off
ZZ plants are quite drought-tolerant and should be watered about once every 2 weeks, only after the top 1 to 2 inches of soil are completely dry. If you are not sure, it is better to under water than over water, as a drier plant is easier to fix.
If you suspect you have over watered your ZZ plant, remove the plant from it’s pot and clean the soil off it’s roots, so you can get a closer look. Using a clean pair of scissors, remove any dark brown or black roots that appear mushy as these are rotten (healthy roots will be light tan). Make sure you wash the scissors after, to avoid spreading the rot to other plants.
Wash out the pot with soap and water and fill it with fresh, new potting soil. Mix in a few handfuls of perlite or gravel to increase drainage. Pots with drainage holes are best to help remove excess water.
Prune the damaged leaves off the ZZ plant and replant in the new soil. If the stem is yellow, clip it off where it grows.
Keep it in an area with bright, indirect sun so that it can dry quickly, and reduce your watering frequency. You may have to move your plant closer to the window for a quicker drying time.
To prevent over watering, always check that the top layer of soil is dry before watering by sticking your finger in, or using a moisture meter.
Remember: if your ZZ plant is in a cooler or darker area, it will require less watering than if it were somewhere warmer or brighter.
2. ZZ Plant Leaves Turning Yellow Due to Under Watering
Since ZZ plants do not need to be watered often, it is very easy to forget to water them for a long time. While ZZ plants prefer to be on the drier side, too little water will lead to ZZ plant leaves yellowing, shriveling up, or dropping off easily.
If the plant’s soil is dry and the leaves look wrinkled or shriveled, your ZZ plant is likely suffering from under watering. On the bright side, under watering is easy to fix and your ZZ plant should bounce back after a quick drink.
Water your ZZ plant enough to wet the soil without drenching it. While it is tempting to over water when you know your plant is dry, do not completely soak the soil. If there is any excess water left in the saucer, dump it out so the plant does not sit in water.
ZZ plants should bounce back within a few days after watering.
If your ZZ plant is somewhere hotter or in brighter sun, it will need slightly more frequent watering.
How to Properly Water ZZ Plants
As you can see, watering ZZ plants properly is crucial to their health. How often you need to water depends on many environmental factors, such as temperature, sunlight, humidity, pot size, soil type, and ventilation.
Start off by watering ZZ plants once every 2 weeks in the summer and once every 3 weeks in the winter. Always check that the top few inches of soil are dry before watering to get an idea if your plant needs moisture. You can adjust the schedule depending on the specific conditions your plant is in.
When you water, soak the plant when the soil is completely dry, and empty out the saucer so the plant does not sit in water. Let the soil completely dry out before you water again. ZZ plants like to be infrequently soaked: do not mist the plant or let the leaves stay wet because that can cause rot.
Furthermore, plant your ZZ plant in a well-draining soil and in a pot with a drainage hole. This will help the soil dry quicker, preventing rhizome rot.
3. ZZ Plant Leaves Turning Yellow Due to Improper Fertilization
Fertilizing too often or not enough can cause nutrient imbalances, resulting in yellow leaves.This is a less common cause of your ZZ plant turning yellow.
Fertilize ZZ plants once a month with a dilute, water soluble fertilizer during their growing season (April to August). To prevent fertilizer burn, do not fertilize more often than once a month, fertilize during the winter, or use a strong fertilizer.
If you suspect you have over fertilized, flush out the soil with a lot of water to remove the excess salts or repot the plant in fresh soil.
Since ZZ plants are tolerant of nutrient poor soil, if you have fertilized your plant at least twice in the past year, nutrient deficiency is unlikely. If you have not fertilized your plant at all, try it once and see if the color improves.
4. ZZ Plant Leaves Turning Yellow Due to Excessive Sunlight
ZZ plants thrive in medium light, and are even tolerant of low light conditions, making them a great addition to any dark corners. However, they are much less happy in bright, direct sunlight, which could cause yellow leaves and leaf burn.
If your ZZ plant is receiving several hours of bright sunlight, this could be why it’s leaves are turning yellow. This is especially likely if your plant’s leaves have brown sunburn spots, which is a sign of excess sunlight.
Move your plant somewhere that receives indirect sunlight. North, east, or west-facing windows are best for this. If you want to keep your plant in front of a south-facing window, cover the window with a sheer curtain to block some of the light and create a barrier for your plant.
Rotate the zz plant every few days, so the growth is even and one side is not exposed more than another.
If only a few of the leaves are yellow or burned, you can prune them to improve appearances.
Watch Out For Pests
ZZ plants with yellow leaves are weakened and unhealthy, making them more susceptible to infestations from pests such as mealy bugs, spider mites or scale. These pests will further weaken your plant.
Keep a close eye on your ZZ plant and any neighboring houseplants for signs of insects (especially check the undersides of leaves because they love to hide in there). If you notice any bugs, misshapen leaves, or sticky webbing on the houseplant, immediately quarantine it.
Wash the plant under a stream of water, such as a hose or shower head, to dislodge the insects. Spray the plant with neem oil, rubbing alcohol, or an insecticidal soap. This will help remove the pests without damaging the plant.
Repeat this process once every few days for a few weeks to completely remove the infestation.
General ZZ Plant Care to Avoid Yellow Leaves
ZZ plants have a reputation for being low maintenance and tolerant of neglect, but there are still a few factors that need to be right for them to thrive.
ZZ plant’s ideal conditions are summarized below:
| Sunlight | Indirect light is ideal, but they will tolerate low light. Does not like direct sunlight, which could cause sunburn. |
| Water | About once every 2 weeks in the summer and once every 3 weeks in the winter. Check that the soil is completely dry before watering. |
| Temperature | 65 – 85 °F (18 – 30 °C). Do not keep in temperatures below 60 °F (15 °C). |
| Humidity | Prefers drier conditions. Do not mist the leaves |
In Summary
ZZ plant leaves turning yellow is a common problem many plant owners face.
4 common causes of your ZZ plant turning yellow are:
- Over watering
- Under watering
- Improper fertilization (too much or too little)
- Excess sunlight
Yellow leaves are a sign of an unhealthy plant. The damage can be fixed if caught quickly. Check your plant for additional clues about the cause so you can fix it:
- If the soil is wet and your plant has yellow, mushy stems, it is likely over watered. Reduce your watering frequency and replant in new, dry soil.
- If the leaves are dry and crispy, your plant could be under watered. Give your plant a good drink.
- If the plant has signs of sunburn (brown spots) on the leaves, it is receiving too much sunlight. Move the plant further away from the window, preferably in indirect sunlight.
- Fertilize no more than once a month with a dilute fertilizer in the spring to summer. If you have fertilized too much, flush out the soil with water.
If only a few leaves are yellow, you can prune them off. If there are a lot, leave some on so that your plant can still photosynthesize.
Have any more questions about ZZ plant leaves turning yellow that I did not answer? Let me know down below!
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