The Aglaonema, or Chinese evergreen, is one of the most rewarding aesthetic indoor plants to grow, and it can be very upsetting to see its beautiful foliage turning yellow! Common causes of this problem relate to overwatering, improper lighting, freezing temperatures, pests, plant diseases, and natural aging of the leaves.
If you are currently faced with yellowing leaves on your Aglaonema, do not lose hope! You may be baffled as to the reason, but this guide will explain the possible causes, as well as providing some tips to revive your plant.
Common causes of yellow leaves on Aglaonema
There are several possible reasons your Aglaonema may develop yellow leaves, but do not lose heart if your indoor plant is losing its vibrant, green color. Check out these common issues so that you can address them appropriately:
Giving your Aglaonema too much water without first checking the soil’s moisture is the easiest way to kill your plant. This common gardening mistake can promote root rot and prevent your Aglaonema from absorbing essential soil nutrients and moisture. This in turn can weaken your plant and turn its green leaves yellow.
Root rot can also attract pests and fungal pathogens. Pests and diseases are the perfect combination to kill any plant – even a tough Aglaonema.
Aside from yellow leaves, the plant’s stems will also turn mushy, making your Aglaonema appear sick and lifeless.
With early intervention, you can still save an overwatered Aglaonema. Follow these tips to help revive your houseplant as soon as possible:
- Remove your Aglaonema from its planter and have a close look at the root ball. Do you see dark, mushy roots that smell like a swamp? Those are dead roots, and should be removed carefully, using a clean pair of scissors or pruning shears. You should also trim any damaged stems and leaves to help your plant heal.
- Spray the roots with fungicide, follow the suggested dosage and directions on the package. Place the plant on some old newspaper and allow the roots to dry.
- Transfer your Aglaonema to a new pot with fresh soil.
- Allow your plant to heal for at least one week before watering again.
- To avoid root rot in the future, never overwater your plant. Wait for the top few inches of soil to dry completely before your next watering.
Withered and yellowed Aglaonemas can also be a sign of underwatering. If you wait for all of the soil to become completely bone-dry, the lack of moisture can cause drought stress and dry leaves.
Water is an essential component for plant photosynthesis. It provides hydrogen so that plants can produce their own food and keep their leaves green. This means that, if your Aglaonema is water-deprived, its natural metabolic processes are hindered. The leaves and stems will also lose turgidity, resulting in a sick-looking, droopy plant.
But do not worry – it is easier to correct problems related to underwatering than those caused by overwatering. These tips should help your dry Aglaonema recover:
- Give your plant a good soak in a basin of water for about 45 minutes. Make sure that the roots and soil absorb enough water through the drainage holes at the bottom of the pot.
- Once the soil is uniformly wet, remove the pot from the tub or sink and allow the excess water to drain completely.
- You may also consider repotting your Aglaonema in fresh soil if the original soil dries out too quickly.
- Maintain a proper watering schedule to ensure that your plant remains hydrated, especially during the hotter seasons.
3. Poor lighting conditions
Your plant’s wellbeing also depends on the amount of light it receives daily.
Sunlight is another key ingredient in photosynthesis, which keeps your Aglaonema green and healthy. With insufficient light, plants cannot harvest enough energy to grow and bloom, and an Aglaonema kept under poor lighting conditions will start to develop brittle stems and yellow leaves.
Too much sunlight, on the other hand, can also be bad for your plant. Direct sunshine can be a tad too harsh for your Aglaonema, and will likely burn and damage the leaves.
The best type of light for your Aglaonema is bright but indirect sunlight. You can achieve this through the following:
- Move your Aglaonema to a window facing east or north. Avoid south- and west-facing windows, as these tend to receive the strongest and hottest sunlight.
- Try to rotate your plant from time to time to ensure that all of its sides receive adequate light for even growth.
- Your Aglaonema can also thrive under artificial grow lights. This is a great option if you do not have the perfect location to provide filtered sunlight. It also means you can grow your plants year-round, regardless of your location or the season.
4. Cold drafts
Aglaonemas are undoubtedly sensitive to cold drafts. Even a chill from a windowsill can kill them pretty quickly if you do not take action fast enough!
Here is what you can do to protect your Aglaonema from cold drafts:
- During the colder months, close the blinds and curtains, especially at night.
- If the night-time temperatures drop below 60 degrees Fahrenheit, try to slip an insulating material in between your plant and the window.
- Aglaonemas cannot tolerate freezing weather or wind, so move your plant away from open doors and windows. You can relocate it to the center of your room to avoid the harsh winter temperatures from outside.
5. Transplant shock
Ornamental plants can suffer from transplant stress, so you must exercise precautions during the repotting process.
Even with precautions, however, a degree of transplant shock is inevitable; the best you can do is to provide optimal care for your Aglaonema while it is recovering. After a few days, its brilliant green foliage should return to normal.
Here are some additional tips to reduce plant stress after repotting:
- Make sure your plant is well-hydrated within the 24 hours before repotting.
- Try to add some horticultural grit at the bottom of the new pot before adding the soil. This will improve the drainage and prevent waterlogged soil.
- Avoid repotting your plants too frequently. It is best to repot your Aglaonema every two years, or when its container becomes too small for its roots.
6. Pests and diseases
Sap-sucking insects and fungal diseases can both inhibit plant growth. If these problems are not treated early on, your Aglaonema can suffer from irreversible damage to the leaves, stems, and roots. The issue can also cause the leaves to yellow quickly as the infestation or pathogens multiply.
These solutions should help save your affected Aglaonema:
- Spray the affected plant with neem oil or insecticidal soap to get rid of pests.
- Clean the leaves from time to time with alcohol diluted in water. Use a soft cloth to wipe away any bugs you see on the undersides of the leaves and on the leaf joints.
- Apply fungicides and copper compounds to treat fungal and bacterial diseases.
- Avoid watering your plants at night. Keep in mind that the leaves should not stay wet for extended periods; otherwise, your plant will become a breeding ground for pathogenic organisms.
- Isolate sick plants to avoid spreading pests and diseases to other, healthy houseplants.
- If the infestation or fungal infection is too severe, it might be too late to save your Aglaonema. At this point, it is best to dispose of the dying plant and start anew.
7. Lack of soil nutrients
Like other houseplants, your Aglaonema obtains its nutrients from the soil. But, unlike in its natural habitat which is rich in organic matter, your plant’s nourishment in your home is limited to what is available in its pot. This is why fertilizers serve as important supplements for the growth of houseplants.
Without adequate nutrients, it can be challenging to encourage the healthy growth of new foliage, even if all the other basic needs like water and sunlight have been met. Nutrient deficiency in Aglaonemas can manifest as smaller leaf growth and yellowing leaves.
How to solve nutrient deficiency in Aglaonemas:
- Add small doses of liquid fertilizer during the growing season. Keep in mind that Aglaonemas are light feeders, and that overfeeding will not encourage faster growth but instead damage the roots.
- If your plant has been overfertilized, flush the soil thoroughly with water to remove the excess salt buildup in the soil.
- It is best to use a foliar spray when you begin treating a nutrient deficiency. Afterwards, you can proceed to root-zone fertilization to continue fixing the problem.
8. Natural aging
If your Aglaonema is yellowing despite providing it the best possible care, the discoloration might just be caused by the natural aging process.
All plants, at some point, produce a few yellow leaves at the bottom as those leaves get older. Eventually, your plant will shed these old leaves to make way for new growth.
If you notice your Aglaonema producing and shedding a few yellow leaves, especially during autumn and winter and especially from the bottom of the plant, this is completely normal.
Should I remove yellow leaves from my Aglaonema?
You should definitely trim the dead and yellow leaves from your Aglaonema, especially if more than 50 percent of its foliage is damaged.
Cutting off the yellow leaves allows your plant to focus its nutrients and energy on the remaining healthy leaves. It will also improve its overall appearance!
To remove the yellowed leaves, make a cut at a 45-degree angle, to prevent water from sitting on the cut. Keep your Aglaonema well-watered and in a location with bright, indirect sunlight to encourage the growth of new leaves.
If your Aglaonema is stressed by one or more environmental factors, the most common sign might be the browning or yellowing of its leaves. Often, this has something to do with overwatering, but other issues such as lack of light, pests, nutrient deficiency, and root damage might also contribute to the yellowing. Make sure to investigate the exact cause before addressing the problem – with the right solution, you can hopefully bring back your plant’s vibrant, healthy foliage!
Image: istockphoto.com / Kittiwut