Dieffenbachia leaves turn yellow when the plant is experiencing some kind of environmental stress. Correctly identifying the cause of the problem is the first step in effectively fixing the yellowing.
The most common causes of yellowing dieffenbachia leaves are overwatering, underwatering, humidity, changes in temperature, too much sunlight, drafts, diseases, pests and lack of nutrients.
In this article, we will discuss the different causes of yellowing dieffenbachia leaves and how to remedy each one.
Why Are My Dieffenbachia Leaves Turning Yellow?
The plant is overwatered
Overwatering the dieffenbachia plant is one of the most common causes of yellowing leaves. When you overwater the plant, there is a proggressive, generalized yellowing of the leaves. Often plants are overwatered because a lot of people overestimate the frequency and amount of water that their plants need. Some people may think that watering the plant with a lot of water today can save them from having to water it for the next few days. This is not how watering plants works. They need to have a regular watering schedule in order to stay alive. This schedule will depend on the type of plant you own, the season, the temperature in the plant’s environment and humidity.
When the plant’s soil is constantly waterlogged, air will not be able to flow around the roots. Plant roots need to be able to dry out because they need access to oxygen for the plant to function as a living being. If the roots are compromised, the plant’s usual processes will become hampered and this will eventually lead to the yellowing of the leaves.
Roots left to soak in boggy water can also get root rot, making the plant more susceptible to fungal diseases.
You can tell if your plant is overwatered by touching the soil around the plant. If the soil is still damp several inches down despite having been watered a while ago, it is probably overwatered. If the plant’s pot is heavy, it might be full of water. If you suspect root rot, you may need to remove the plant from the soil and check the roots. If there are brown or black roots that feel soft and mushy, you have root rot.
If the plant is overwatered but does not have root rot, just lengthen the time between watering and make sure the soil is dry before watering it again. If the soil in the pot is too compact, you could repot it using new, well-draining soil and a pot that has drainage holes at the bottom. This allows any excess water to flow out of the holes and dries out the soil faster. Make sure you give the plant less water during the fall and winter compared to spring and summer, because soil will not dry out as quickly in cold weather.
Underwatering
While giving the plant too much water is bad, so is neglecting to give it any water at all. Underwatering can also lead to yellowing and even browning of dieffenbachia leaves. This often affects the newest and oldest leaves first, as well as the leaves at the bottom of the plant.
Even if dieffenbachia is reasonably drought-tolerant, you still need to be aware of the signs of an underwatered plant. Not only are the leaves yellow or brown; the soil is also bone dry. The pot also tends to feel lighter.
Thanks to being naturally drought-tolerant plants, dieffenbachia recover quickly from being underwatered. You just need to return to the normal watering schedule that worked for the plant. Try not to remove the yellow or brown leaves while the plant is recovering because it might add stress that the plant does not need.
Humidity
The dieffenbachia is actually more tolerant of low humidity than many other plants, but it can still develop yellow leaves if exposed to low humidity for long periods of time.
Yellowing leaves is usually due to a change in location from high to low humidity. This change in atmosphere requires the plant to make a rapid adjustment to its new surroundings, leading to transplant stress.
Transplant stress is very common in plants that were grown in nurseries or greenhouses with perfect living conditions. When you bring the plant into your home, which is a lot more arid than the nursery, the plant will respond to this change of location.
Fortunately, these changes are temporary and the plant will soon adapt to its new surroundings. You can aid its transition by providing it with the closest possible living conditions to its natural habitat.
Changes in temperature
Dieffenbachia plants prefer to be in temperatures that are somewhere between 50 and 80 degrees Fahrenheit. If it gets any lower or higher than these temperatures, the plant will display signs of stress such as yellowing leaves. This is because the plant is unable to function properly outside its preferred temperatures.
The inside of most homes have no problem adhering to these temperatures. Changes in temperature are most obvious in the summer or near a drafty window in the winter. A dieffenbachia that is left out in the summer sun but is not moved indoors when autumn comes can also be susceptible to the effects of temperature changes.
Avoid temperature stress by placing a thermometer near your plants so you can easily check the temperature when you need to.
Lighting issues
The dieffenbachia plant prefers bright, indirect light, and too much direct sunlight can dry it out and burn it. Not only is providing the correct amount of light important in order to keep it healthy; the amount of light the plant gets can also affect how much and how often you need to water your plant, too.
You can prevent light-related problems by placing your plant in a spot that is not near the path of direct sunlight. It would much rather be in an area out of direct light for most of the day and only exposed to direct light for one to two hours a day.
Remember that changing seasons can change the amount of light and heat that reaches your plant. You may need to change your plant’s location every couple of weeks to make sure it gets its preferred light year-round.
Drafts
If you cannot figure out the cause of the yellowing leaves despite ruling out all the possible reasons listed above, you might want to check if there is a draft flowing through the area where your plant is kept. Is the plant under an air conditioning vent? Maybe it is placed right next to a heating vent. Sometimes a leaky window can also be enough to cause these changes to your dieffenbachia.
You can correct this by transferring the plant to a different spot in your house that does not have any drafts hitting it. Eventually, your plant will recover and return to its original color.
Disease and pests
Another reason your dieffenbachia leaves are turning yellow could be disease and pests.
There are several fungal or bacterial afflictions that can affect your plant. As mentioned above, overwatering can make the plant more susceptible to a host of diseases. Prevent these diseases by making sure you do not overwater your plant.
The most common pests that attack your dieffenbachia plant are spider mites, scale insects and mealybugs. Make sure you check your plant regularly for any pests so that you can stop the infestation in its early stages. These bugs will pierce the leaves and feed on the sap, leaving yellow markings that spread out the more they feed on the plant.
You can get rid of these insects by using an insecticide or by applying neem oil to the leaves of the plant. Make sure you isolate the infested plant so that the pests do not make their way to the other plants in your garden.
Lack of nutrients
A lack of certain nutrients in your plant can also result in the yellowing of leaves. The most common deficiencies are phosphorus and nitrogen.
Your plant can suffer from a nutrient deficiency if it has been in the same soil and pot for years. Even once-nourished soil loses its nutrients over time, because you are gradually washing them away as you water your plant.
Fertilize your plant to help it grow and thrive, but make sure you do not overdo it because that can lead to nutrient toxicity. Fertilize your dieffenbachia every two or three weeks during the growing season with a water-soluble fertilizer at half-strength.
Conclusion
A dieffenbachia with yellow leaves is indicative of a problem in the plant’s environment that is causing it stress. You will need to identify this problem correctly in order to remedy it.
The most common causes of yellowing dieffenbachia are overwatering, underwatering, humidity, changes in temperature, too much sunlight, drafts, diseases, pests and lack of nutrients.
Dieffenbachia are low-maintenance and hardy plants, and as long as you provide them with their basic needs, you will have no problem growing them at home.
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