ZZ Plant Yellow Leaves

ZZ plants (Zamioculas zamiifolia) are perfect for the neglectful or forgetful gardener. Suited to those that often forget to water, they are drought resistant, tough, low-light tolerant, undemanding beauties. Unfortunately, even though these plants are super hardy, they can suffer from various issues. One of these issues is yellowing leaves.

There are several reasons why a ZZ plant’s leaves are turning yellow. These include watering issues, both over and under-watering, prolonged exposure to high levels of direct sunlight, temperature extremes, nutrient deficiencies, and pests. Each of these problems is fixable if caught in time.

ZZ plants have fleshy stems and oval-shaped leaves, reminding you of stylized feathers. Leaves changing color is often the first indication of an underlying problem with your plant. So if you notice that your ZZ plant’s leaves are turning yellow, the best course of action would be to determine the problem so that you can implement a solution.

Why Are Your ZZ Plants Leaves Turning Yellow?

Even though your ZZ plant is super hardy, they have some essential preferences. If these preferences are ignored or not taken seriously, it can negatively affect your plant, which will often show up as yellowing leaves. In some cases, if your plant is unhappy, it can lead to other issues.

The following is a list of six primary reasons as to why your ZZ plants leaves are turning yellow:

  • Over-watering
  • Under-watering
  • Incorrect lighting
  • Temperature extremes
  • Nutrient deficiencies
  • Pests
ZZ plant

ZZ Plant Leaves Turning Yellow Due To Over-Watering

One of the primary causes of yellowing leaves on a ZZ plant is over-watering. ZZ plants prefer their soil to dry out before being watered again. Too much water can cause fungal rot in your rhizomes, your plant’s food, and water storage systems.

Too much water can also prevent your plant from breathing correctly. Plants breathe through their roots. If there is too much water, your plant’s roots will be unable to absorb the soil’s gasses, which will result in your plant slowly suffocating.

To properly diagnose your ZZ plant with over-watering, there are several signs you can look out for:

  • Wet topsoil
  • Wilted looking plants
  • Browning stem
  • Young leaves turning brown
  • Rotting roots

The Solution

If you have found that your ZZ plant is exhibiting a number of these signs, the best option for you is to hold off on your watering until the soil is dry. Then resume watering every seven to ten days, making sure that at least 50% of the topsoil is dry before you water again. Purchasing a moisture meter will help you check your plant’s moisture levels before watering again.

If your ZZ plant suffers from root rot, you will need to give it a bit of a clean-up and re-pot it. The best way to check for root rot will be to remove your plant from its pot to look at the roots. If they appear white, they are healthy. If they appear brown or sludgy, they suffer from a fungal infection and root rot, which can lead to your plant’s demise.

In this instance, you will need to remove the rotting roots with a clean pair of disinfected scissors, get as much soil out of the root ball as you can, as this soil is also infected. Wash your pot out with warm soapy water and dry it before replacing your ZZ plant with new potting soil.

Users Also Read: ZZ Plant Varieties

ZZ Plant Leaves Turning Yellow Due To Under-Watering

Your ZZ plant can handle extended periods without being watered, but it will eventually show signs that it needs a bit of nourishment. These signs will often show in the leaves starting to turn yellow. Other symptoms of under-watering include:

  • Leaves shriveling up
  • Brown edges on leaves
  • Leaves falling off

The Solution

The best thing is to give your plant a good soaking in this instance. Pour water until it starts to drain out of the holes in the bottom of your pot. Don’t let your ZZ plant sit in any water as this plant is not fond of wet feet.

Hold off on watering your plant again until it is at least 50% dry to almost completely dry, and this should take around 7 – 10 days. It would be best not to fertilize your ZZ plant during this time, as fertilizing on dry soil is not always beneficial to your plant. Rather wait till your next appropriate watering time.

An inconsistent watering regime is also not beneficial for your plant. Once you have started to water again, it would be best if you tried to keep up your schedule, making sure you don’t water too much at one stage and then forget again for a few weeks and then water too much. This cycle will also lead to yellowing leaves.

ZZ Plant Leaves Turning Yellow Due To Incorrect Lighting

zz plant near window in the sun

ZZ plants are very particular about how much lighting they prefer. These plants thrive in medium lighting conditions, they will even tolerate low-lighting conditions, but they do not appreciate being in areas where they receive excess light.

If your ZZ plant is in an area receiving more than four hours of indirect sunlight, this could be too much for it, and its leaves can start to turn yellow. Other signs of too much light include:

  • Sunburn brown spots on the leaves

If your plant is in a relatively bright area and you notice the leaves turning yellow and brown spots appearing, this can be due to incorrect lighting.

The Solution

The best practice would be to relocate your ZZ plant to an area that will receive less indirect sunlight. If this is not a possibility, you can make it a shade covering using material such as lace or sheer curtains.

ZZ Plant Leaves Turning Yellow Due To Extreme Temperatures

ZZ plants prefer hardiness zones 9 -10, tolerating temperatures which range from 50° – 90° Fahrenheit (10° – 32° Celsius), temperatures above or below this will cause discomfort to your plant, which it will show you through its leaves turning yellow.

The Solution

These plants typically do not like cold temperatures. Anything below 45° Fahrenheit (7° Celsius) will cause your plant to suffer. Try to make sure that your plant is not in a location where it will be subjected to drafts or in any area of your home that is too cold.

It would help if you were especially careful of temperatures that might drop too low at night, the optimum temperatures for your ZZ plant range between 76° and 87° (24° and 30° Celsius).

Read more: ZZ Plant Too Much Light

ZZ Plant Leaves Turning Yellow Due To Nutrient Deficiencies

Leaves turning yellow on your ZZ plant can be due to a lack of nutrients in your plant’s soil or because the soil pH is too high, and therefore your plant roots will be unable to absorb the nutrients present in the soil.

Too high nutrient levels from over-fertilization can also cause yellowing leaves on your ZZ plant.

The Solution

The best option here is to buy a soil test kit that can determine your soil’s pH. ZZ plants prefer soils with a slightly acidic to neutral pH. If your soil pH is too high, you can add sulfur to decrease its pH levels.

Another way to combat and prevent nutrient deficiencies in your plant is to have a regular fertilization routine during your plant’s growing months. The best practice for fertilizing your ZZ plant is to give it a feed every two or so months with a half-strength houseplant fertilizer.

Remember not to fertilize your plant during the winter months. If you think that you have been fertilizing too much and your leaves have started to turn yellow, you can always give your plant a flush.

Flush your plant by pouring enough water into your container so that it starts to flow out the bottom. Leave it for a bit and repeat the process two or three times to remove any excess salts in your soil.

ZZ Plant Leaves Turning Yellow Due To Pests

Stressed or weakened ZZ plants are more susceptible to pest infestations. There are various kinds of pests, the sucking bugs such as spider mites, make holes in your leaves and stems, sucking out the plant’s nutrients and moisture, and causing rapidly yellowing leaves on your ZZ plant.

Pests such as mealybugs, scale, and spider mites are frequent problems when house plants are concerned. If not dealt with early, they can increase and accelerate the yellowing of your plant’s leaves, especially in cases where your ZZ plant is already unhealthy due to moisture issues or nutrient deficiencies.

The Solution

neem oil

Once your ZZ plant has developed a pest problem, it is best to treat it as soon as possible. You can spray the infected areas with insecticidal soap or diluted neem oil in a spray bottle.

Conclusion

ZZ plants are hardy plants that prefer less water and medium lighting conditions. They are easy to care for, but that doesn’t mean they don’t come with their issues, such as yellowing leaves.

There are six primary causes of a ZZ plant’s leaves turning yellow. Luckily they are all treatable if you catch them in time. Once treated, your ZZ plant should bounce back to its usual happy self in no time.

References

https://extension.illinois.edu/blogs/extensions-greatest-hits/2007-08-28-yellow-leaves-can-indicate-plant-problems

https://www.thespruce.com/zz-zanzibar-gem-plant-profile-4796783

https://homeguides.sfgate.com/care-zamioculcas-zamiifolia-plant-yellowing-leaves-45800.html

https://bloomscape.com/common-issue/why-does-my-zz-plant-have-yellow-leaves/

https://plantcaretoday.com/zz-plant-yellow-leaves.html

https://www.gardeningknowhow.com/houseplants/zz-plant/caring-for-zz-plant.htm

https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm

https://worldofsucculents.com/care-yellow-leaves-zz-plant-zamioculcas-zamiifolia/