Our houseplants can’t talk to us, but they can tell us when something is wrong. One sign that a houseplant isn’t thriving is yellowing leaves — when their normally green leaves turn a dull shade of yellow.
What does houseplant leaves turning yellow mean, and how can we treat them? Let’s take a look at the most common causes of yellow leaves on houseplants.
When it comes to yellowing leaves on houseplants, the number one culprit is improper watering.
When plants are underwatered, they begin dropping leaves in an attempt to conserve water. The less leaves a plant has, the less water it needs. So if your plant’s leaves are turning yellow and starting to drop off, you might need to water it more regularly.
But what if you are watering your plant regularly, and it still has yellowing leaves? There’s a chance that you are watering your plant too much. Flooding your houseplant with too much water doesn’t give its roots a chance to breathe. Drowning your houseplant’s roots in water can also cause yellowing leaves or loss of leaves.
To solve this dilemma, I recommend gauging your plant’s soil and adjusting your watering habits accordingly. If your plant’s soil is regularly dry, try watering it more frequently. If its soil stays moist, try letting it dry out completely before watering again.
Somewhat related to improper watering, poor drainage can also be a cause of yellowing leaves on your plants.
Too much water can definitely cause yellowing leaves and other problems for your houseplants. However, any amount of water can be harmful to your plants if that water can’t drain properly out of the pot.
To avoid this, you will first want to make sure that the pot your houseplant lives in has plenty of drainage holes. Without drainage holes, water will collect at the bottom of your pot, which can cause root rot in your plant.
You will also want to make sure that you are using soil that drains well, meaning that your soil doesn’t hold too much water. Soil that holds too much moisture can also lead to yellowing leaves and eventually root rot.
To improve the drainage of your soil, mix in organic matter like compost or perlite. You can also purchase soil mixes made especially for houseplants, which are designed to have the right amount of drainage for your plants.
Another cause of yellowing leaves in houseplants is compacted roots. Compacted roots occur when plants begin to outgrow their pots, sometimes growing out from the drainage holes in the pots themselves. When roots are compacted, they have trouble accessing enough oxygen and can begin to rot. This can cause yellowing leaves, and eventually the death of your plant
If you have a plant with compacted roots, it’s time to repot! Slide your plant out of its current pot and examine the roots. Healthy roots will be whitish yellow; unhealthy roots will be dark and will sometimes have an unpleasant odor. Trim off any unhealthy roots from your plant, and then place it in a larger pot, filling in the spaces with houseplant-friendly potting soil.
When a house plant’s soil pH is too low, it cannot access the nutrients that are available in the soil. This can cause a houseplants leave to turn yellow.
Most houseplants like a neutral soil with a pH of 6.0 to 7.0. Some houseplants, like the croton, African violet, or rubber plant, prefer more acidic soil with a pH of 4.5 to 6.0.
Not sure of your soil’s pH? A soil testing kit can help you determine where you stand. If you find you need to adjust soil pH, additives like baking soda or limestone can help. Here’s some more info on determining and adjusting soil pH.
Lack of Light
Another issue that can cause a yellow leaf to pop up on your houseplants is a lack of light. If you see yellow leaves only on the side of your plant that is away from the sunlight, this is probably the cause.
To remedy this, it’s a good idea to rotate your plant regularly so all sides get equal sun. If you’re still seeing that a lack of light is causing a yellowing leaf or two to show up, consider supplementing with artificial grow lights.
A cool breeze feels great to you and me, but it’s not so delightful for most houseplants. A chilly draft can cause the leaves on houseplants (particularly on a tropical plant) to yellow and drop.
Luckily, this problem is one that is easy to remedy. Moving plants away from air conditioner vents or drafty windows should prevent leaves from yellowing due to cold. If this move means your potted plant won’t be getting enough sunlight, consider investing in a grow light — I use this one.
Aging is a fact of life for all living things, including houseplants. While many houseplants can live for decades (theoretically), they do sometimes show signs of age. In some cases, leaves will yellow and drop off as newer leaves are growing. This is just part of your plant’s natural life cycle.
Lack of Nutrients
If your soil pH is good, but you are still seeing yellow plant leaves, your plant might have a nutrient deficiency. How can you know which nutrient your plant needs? The clues are in the leaves themselves.
If you see established inner leaves turning yellow, your plant most likely has a nitrogen deficiency.
If the edges of leaves are turning yellow, you may have a potassium deficiency.
If your plant leaves have yellow patches, you may have a magnesium deficiency.
If your plant’s newest leaves are turning yellow, you may have a sulfur deficiency.
Fertilizer is the easiest way to manage these deficiencies. A general houseplant fertilizer can help resolve most issues. If your plant is lacking in magnesium or sulfur, using epsom salt as fertilizer can be particularly helpful.
Unfortunately, sometimes yellow plant leaves are the sign of a virus infection in your plant. If this is the case, you will probably also see the effects in the entire plant, including the flowers and stems.
Viral infections in houseplants can be very hard to treat. In some cases, using fungicide can help. In other cases, it may be that trying to propagate a new plant from healthy cuttings is your only option.
If you suspect that your plant has a viral infection, you will want to make sure you move it away from other plants, because viral infections can spread between potted plants.
If your houseplant has yellowing leaves, you should pay attention — but don’t fret. There are many causes of yellow leaves, and many of them have simple solutions that will get your plant back to its green beauty in no time. Start with your watering habits and keep working through until you find what works for your potted plants.