9 Common Causes of Yellowing Plants (and How to Fix Them)

When a plant yellows, there is still plenty of time to heal it. The reasons it can change color vary, and each cause has a unique solution. Uncover why yours is having problems and learn how to prevent them in the future with these tips. 

1. Dehydration

Underwatering causes issues other than yellowing, including wilting and loss of strength. The leaves can start to curl as they yellow, which is a common sign that your plant is thirsty. If you have a moisture tool, insert it into the soil to see if your suspicions are correct. You can also check how dry it is with your hands, ensuring you don’t probe too much into the roots. 

Solution: Alter the watering schedule to be more attuned to the specific species. Set reminders on your phone or calendar until you get into the habit. Eventually, the plant will recover.

2. Overwatering

The opposite can also turn leaves yellow. If there is too much water, the plant can’t get the nutrients it needs from the soil. The excess acts like a barrier between the roots and what they need to survive. Instead of curling, the bottom of the stem could start to mold. 

Solution: Let it dry out for a while and adjust your watering habits. You may also need to get a pot and plate for adequate drainage or new potting soil that prevents waterlogging.

3. Nutrient Deficiency

Overwatering can cause nutrient deficiency, but your plant may also have them even with perfect watering schedules. They need iron, magnesium, nitrogen and more. Just like humans, they need a healthy balance of many things. Some early warning signs include yellowing in these locations:

• Veins and branches for low iron
• Older leaders for magnesium
• Leaf edges for potassium
• Overall yellowing for nitrogen

Solution: If you don’t know what nutrient the plant is missing, perform a soil test to prevent the guesswork. You can start by using better fertilizers or creating compost, which supplements inadequate soil with what it needs. If you only have one missing nutrient, there are specific fertilizers for this, too. 

4. Inadequate Drainage

Root rot occurs if water fails to travel through the soil. Sometimes, you want soil to hold onto water as much as possible, but it may not always do so. Carefully lift your plant to see if the roots have sunk and collected in a bundle at the bottom of the container. If so, your plant has overgrown, and the root system may also hinder efficient drainage. 

Solution: Adjust the soil to encourage greater flow, and repot overgrown plants in larger containers made from the right materials to promote movement and expansion. Supplements like sand can also help.

5. Not Enough Light

Light is essential for photosynthesis, and plants sitting in dark corners could turn yellow because they are not engaging in that process. Research the variety that is starting to turn and see what its preferred light conditions are. Some enjoy low-light areas, while others will quickly wilt.

Solution: Experiment with different locations for yellowing plants so they receive various amounts of light. Place them in natural light if possible, but you can also install grow lights if access is limited.

6. Pests or Illness

Take a close look at the soil, petals, stems and leaves of the plant. You may even need a magnifying glass, as some pests are difficult to see. Spider mites, aphids and worms can take nutrients away from leaves and cause them to yellow. If you see something, remain calm — there are many ways to combat an infestation.

Solution: Discover the species afflicting your plants as fast as possible. Then, get a targeted solution. Some include neem oil, insecticidal soap and various do-it-yourself mixtures. If this is a repeat concern, consider an organic, nontoxic pesticide as a preventive solution.

7. Environmental Stress

Temperature and humidity are two crucial metrics to maintain for happy plants. Extremes can lead to drooping and yellowing leaves. Many plant enthusiasts keep a thermometer and a humidity meter near their most finicky species so they are always aware of conditions. Over time, you become aware of the ideal ranges for specific varieties.

Solution: Move plants away from environmentally stressful locations. These could include:

• Cold and drafty areas, like under vents
• High-moisture zones, like bathrooms
• Places with constantly changing temperatures, like near kitchen appliances

8. Acidity and Alkalinity

Imbalances in pH change how well the soil operates. If it is too high or too low, it will fail to deliver the nutrients and water the plant needs optimally. You may be able to determine the problem in a few ways. Homes with hard water could unintentionally be putting too many minerals in the soil, affecting pH. Additionally, overfertilization can bog down plants, making them too acidic. 

Solution: Fortunately, a straightforward test can help you discover your soil’s pH. Take action based on whether it is too high or too low. Options include wood ash or various types of lime, which can heighten, lower or stabilize pH. If your problem’s source is hard water, get a filter or recycle rainwater to treat your plants.

9. Exposure to Ethylene Gas

If you have potted and indoor plants near the kitchen, there could be a sneaky reason why yellowing starts. Ripening vegetables and fruits produces tons of ethylene gas, which can change leaves’ colors. The area may have poor ventilation, giving the gas nowhere to escape.

Solution: Move plants away from areas where you keep ripening fruit. You may also try opening a window or introducing a cross-breeze into the area to keep the gases away from them. 

Getting the Green to Come Back

A yellowing plant is fixable, despite how alarming it can look. Fortunately, every cause has a noticeable catalyst, allowing you to narrow down the possibilities quickly. All you need to do is be patient, and your plants will return to their colorful glory in no time. Plus, you can use this knowledge to prevent yellowing from happening again.