Poor drainage or improper watering requirements

Too much or too little water is one of the main reasons behind yellow leaves. In soil that is too wet, roots cannot breathe properly. They suffocate, close themselves off and therefore can no longer transport water and nutrients that plants need. Too little water or even drought has a similar effect. With too little water, plants cannot absorb the essential nutrients they need, resulting in yellow leaves.

Fortunately, preventing or solving a water problem can be super easy. It all starts with a well-drained soil. Always choose (grow) pots with drainage holes and keep a close eye on the saucer or plant pot. Always pour away excess water to prevent your plant from getting wet. If necessary, add organic material to improve soil structure and drainage. Read all about the perfect potting soil.

Before you water your plant, the 'finger test' is a handy method to check whether your plant already needs water. Stick your finger a few inches into the soil and only water your plant if the soil feels dry.

Pests or disease

Common pests such as spider mite, aphid or mealybug can cause yellow leaves. The sap-sucking insects puncture holes in the leaves, causing them to become yellow or misshapen. Most pests leave clear signs on the leaves, making it easy to recognize an infestation. So check your houseplants regularly for pests and do not forget the underside of the leaves, the stems and the potting soil. Have you spotted a pest? Place the plant in quarantine and read all about the pest on our PLNTSdoctor page! Diseases can also cause yellow leaves in houseplants. Pathogens that cause root rot will generally cause the leaves to yellow and wilt. Other diseases can cause leaf spots of various colors.

Light

A lack of sunlight is a common cause of yellow leaves in houseplants. Especially if you place them away from a window, such as in the hallway. When a plant doesn't get enough light, photosynthesis will decrease causing the leaves to turn yellow. More light also means more photosynthesis: an easy solution!

For certain species grow lights can also be an option.

Heat and cold

Temperature also contributes to the color of the leaves. When it is too hot or too cold leaves can change color. Tropical plants are not used to the cold and also do not cope well with low temperatures or drafts. This in turn will cause leaves to yellow. Is your plant exposed to warm or cold temperatures for a longer period of time? Then the leaves will turn brown.

Nutrition

Yellow leaves on plants can also be a good indication of their nutrition. Common nutrition problems are under- or over-fertilization. So it's important to pay close attention to how much fertilizer you can use. Often plant enthusiasts tend to give a little more so their plant can grow nicely. Unfortunately, in this way you create a toxic environment which 'burns' the leaves of your plant, so to speak, and eventually causes them to turn yellow.

Old leaf

Luckily, a yellow leaf does not always mean that something serious is going on. Does a leaf occasionally turn yellow on the underside of your plant? Then your plant probably just wants to get rid of its old leaves in order to make new beautiful leaves again! Unfortunately, yellow leaves can't turn green again. The best thing you can do if your plant is suffering from yellow leaves is to cut them off so your plant can focus all of its attention on growing new, green leaves!