Zamioculcas zamiifolia or the ZZ plant is a remarkably easy-care plant similar to cacti, succulents, or orchids when it comes to care.
These plants like a light, airy, breathable growing medium and they cannot tolerate wet feet.
Unlike orchids, succulents, and cacti, the ZZ plants thrives in low light settings.
You’ll have very few problems with this plant, but yellowing leaves are a common symptom which will tell you when problems are present.
There are several reasons why the leaves of your ZZ plant may begin to turn yellow.
In this article, we review the causes of this common problem and share advice to help you avoid or treat it. Read on to learn more.
When you overwater ZZ plants, as with most plants, root rot may ensue.
When this happens, the roots can no longer uptake nourishment properly, and this causes yellow leaves.
To determine whether overwatering is the cause of your problem, simply check your soil.
If you poke your finger into the top inch of soil, and it is wet, overwatering is likely to be your problem.
To water your ZZ’s correctly, you should allow the top 1” inch of growth medium to dry completely.
Pour water through the soil just as you would with a cactus or succulent.
Don’t allow the plant to stand in water for any significant period.
Be sure to tip any excess water out of the plant’s drainage saucer.
Even though drought-resistant ZZ plants don’t need a lot of water, they do need some!
If you have neglected your plant for an extremely long time and the soil has become completely dry, your plant will suffer and will let you know with yellow leaves.
Soil feeling dry to the touch and a pot feeling abnormally light when you lift it indicates a need for water.
Give your plants a good soaking, but don’t fertilize excessively dry soil.
If you want to provide fertilizer, wait until the next appropriate watering time and use a diluted (half strength) solution.
What Is The Right Amount Of Water for A ZZ Plant?
It’s not possible to recommend a precise schedule because every situation and the setting is different.
The amount you will need to water your plant depends a great deal on some factors including:
- Air Circulation
The more light, heat, and air circulation your plant receives, the more water it will need.
Dimly lit, humid; still settings will require less water.
If the soil you are using is heavier than is ideal, your plant will need less moisture.
If you have an ideal, light, airy substrate for your plant, you’ll need to water a little more often.
Generally speaking, weekly watering during the plants growing season (spring, summer, and autumn) and twice-monthly watering during the winter should be all right.
Improper Nutrition Can Cause Yellowing Leaves
Zamioculcas is hardy and undemanding, but they do need a bit of fertilizer from time-to-time.
Choose a water-soluble, balanced houseplant fertilizer and mix it up at half strength.
Apply it no more than once a month.
Fertilizing a couple of times a year (once early in the spring and once around mid-summer) is an ideal schedule.
Yellowing leaves are sometimes caused by too much nutrition or too little.
If you have been fertilizing your plant excessively, give it a rest.
Give your plant a thorough watering allowing fresh, clean water to flow through the soil for several minutes to rinse out excessive fertilizer.
If it’s been a while since you’ve repotted your ZZ, starting over again with the fresh, new potting soil will also take care of problems caused by either under fertilizing or over-fertilizing.
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Zamioculcas Zamiifolia Is A Shady Place Plant
Another cause of yellowing leaves is excessive light.
Zamioculcas like to be in partial shade or areas with moderate indirect sunlight.
If your plant is receiving more than four hours daily of direct sunlight, it’s too much.
This will cause sunburn and yellowing leaves.
If you believe excessive light is causing your plant’s problem, naturally you should relocate it to a setting providing gentler lighting.
Alternately, if relocating the plant is not possible, you may wish to put a sheer or lace curtain over the offending window to provide some shade.
Temperature Extremes Can Cause Yellowing Leaves On Zamioculcas
ZZ plants are winter hardy in USDA hardiness zones 9 through 10.
These plants can tolerate temperatures ranging from 50° – 90° degrees Fahrenheit (10° – 32° C), but wildly fluctuating temperatures will cause the plant to suffer and the leaves to yellow.
Ideally, you should keep your plant at comfortable room temperature during the day and don’t allow the temperature to drop below 50° degrees Fahrenheit (10° C) at night.
12 Steps To Treat A ZZ Plant With Yellow Leaves
- Begin by removing the damaged plant from its pot. This is especially true if the problem has been caused by excessive water, but a repotting into fresh soil can benefit any ailing ZZ plant.
- Carefully shake and brush the old soil away from the plant’s root ball and throw the old soil away. If your problem is caused by root rot, you don’t want to reuse soil infected with fungus.
- Examine the plant’s roots under good lighting. If you find any soft, mushy areas clip them away with sharp, sterilized pruning shears. Dispose of this fungus-infected tissue properly. Don’t throw it in your compost, toss it in the trash.
- Sterilize your shears and examine the leaves and stems of the plant. Clip off any yellowed foliage. If you find yellowed stems, clip them off at the point where the stem emerges from the tuber.
- If you have found root rot is your problem, drench the tuber and the roots thoroughly with a solution of thiophanate – methyl, or other fungicidal treatment. No matter what sort of product you choose, be sure to follow packaging directions very carefully.
- Have a brand-new container ready. The best containers for ZZ plants provide good air circulation to the roots and tubers. The best materials are terra-cotta or hypertufa pots. Even with these porous materials, the container you choose must also have ample drainage holes.
- Use fresh, light, airy houseplant potting mix. A good mixture is half perlite and half succulent potting mix. Put a layer of pebbles or packaging peanuts on the bottom of the pot for extra drainage. Add a layer of your potting medium. Place the plant in the container and backfill around the roots and tuber with fresh growing medium.
- Place the recovering plant in a setting where it will remain consistently warm with low, indirect lighting for about a week. During this time, do not water. Allow the plant to stay dry so the fungicide you have applied will have a chance to work.
- When your plant has had a week to recover from its ordeal, place it in the best setting possible. Ideally, your ZeeZee plant will be happiest with consistent temperatures between 80° – 87° degrees Fahrenheit (27° – 30° C), bright indirect lighting, and good air circulation.
- Begin a responsible and effective watering schedule by giving your recovering plant a complete watering. Remember not to water again until the top 1″ inch of soil is dry.
- Your plant will not need fertilizer at this time because it is in fresh soil. Depending upon the time of year, you may not need to fertilize until early in the upcoming springtime. Remember not to fertilize any more frequently than once a month, and no less than two times yearly.
- If you are able to give your ZZ plant a vacation outdoors in the spring and summer, do so. Your plants will thrive in a protected outdoor setting providing bright, indirect natural lighting and fresh air.