Your cart
Close Alternative Icon
Join the FOLIA PLANT CLUB and get rewarded every time you shop with us! Join the FOLIA PLANT CLUB and get rewarded every time you shop with us!

Ask A Plant Pro: Yellowing Leaves

Photo-hanging Pothos plant with some yellowing leaves visible in the center, towards the base of the plant

Every month on our Instagram account we will open up a question box for you to submit your plant questions. Think of it like a Dear Abby column but for plant-related questions. If we select your question, we'll send a treat to your Instagram inbox.

Dear Plant Pro: My plant's leaves are turning yellow. How do I accurately identify what is wrong? 

-Stumped in South LA


Some version of this is one of the most frequently asked questions I get, and I understand why - when leaves start turning yellow it's alarming and it's natural to spring into problem solving mode and figure out what you're 'doing wrong'. The tricky part is that yellow leaves can be a 'symptom' of a number of different issues, so it takes a bit of detective work and ruling issues out in order to get to the root cause. 

When yellow leaves appear, it's important to first realize that yellow leaves don't always mean you've made a care error, or that there's something wrong with your plant.

All plants shed older leaves naturally over time, so if it's just one or two leaves, and they're close to the base of the plant (where the oldest leaves are), don't panic - this may be the natural aging process of the plant in action. 

 

If the yellowing leaves aren't older leaves, or there's more than a few of them, then you'll want to start the investigation process. Begin by running through this list to determine if any of these factors may be at play and follow the corresponding action steps, waiting a week or two to see if there's any change - which will confirm your diagnosis. 

Common Reasons Plant Leaves May Turn Yellow Action Steps
Lack of light
Light is the most important factor for healthy plants and a lack of light often manifests as yellowing leaves.
Double check the light needs of the particular plant and if you're not providing it with enough, adjust the placement of the plant to get it into the correct level of light. 

Adaption to a new environment: As a plant adjusts to new conditions (especially when moving from a bright greenhouse to our not-so-bright homes), it's natural for some yellowing and leaf-loss to occur.

Ensure you're creating the optimal conditions for the plant (enough natural light, adequate humidity, correct watering, etc). If you're not able to create optimal conditions and the plant is a species that can tolerate less ideal conditions (like an Epipremnum [Pothos] or ZZ Plant), then you just need to accept that the plant will lose some leaves as it finds an equilibrium with the available resources. 

Incorrect watering: watering goes hand-in-hand with light - the more light a plant gets, the faster it will use the water stored in the soil. If the balance between how much water is in the soil and the amount of light the plant receives is off, some plants will exhibit yellow leaves as a sign of that imbalance. This goes both directions - too much water can cause yellowing, but too little water can as well. 

First, be sure you're using sound watering practices. This means:

  • Use a pot/planter that has drainage holes, or a cachepot setup where you can take the plastic nursery pot out to water
  • Evenly and thoroughly saturate the soil every time you water. Make sure you move the water around as you apply it across the surface, and use enough volume of water that all of the soil is saturated and water is freely flowing through the drainage holes (the pot will feel quite a bit heavier when the soil is saturated)

If you've got your watering method dialed in, you'll also want to ensure your timing is correct. I advise against watering on a schedule and instead recommend checking the soil on a schedule and only watering when it's at the correct level of dryness. This will vary from plant to plant, so if you're not sure how far your plant wants to dry out between waterings, look it up or ask.

Pests: some pests can cause leaf yellowing as they sap nutrients from the plant while they feed. Different pests will cause different kinds of damage to leaves - some leave spots or a pattern, others a little trail, and some cause even yellowing across the whole leaf. 

Anytime you have a mystery plant problem, it's always a good idea to check for pests - just in case. The most common houseplant pests are spider mites, mealybugs, thrips, scale, aphids, and fungus gnats. Learn to identify each of these because you're likely to encounter them at least once in your plant parenthood journey. Do an internet search to see images of each in various stages of their life cycle and remember that most are very small so you may need to use magnification in order to properly identify them. 

Once you've identified the pest, follow the corresponding course of treatment as well as prevention guidelines. My book, Houseplants For All, has an entire section dedicated to pest management, and we'll be adding more content to the blog to help with pests in the coming months. 

Nutrient deficiency: over time, the available nutrients in potting mix are depleted and since an indoor plant or containerized plant can't pull nutrients from their surrounding environment like a plant growing in the ground outdoors can, we have to add those nutrients back to the soil via fertilizer. Too little or too much of a specific nutrient can manifest in various leaf discolorations, but the most common nutrient related issue in houseplants is either a lack of fertilizer overall, or too much fertilizer. 

If your entire plant appears pale in color (even if not exactly yellow), or growth seems stunted, and you know you haven't fertilized in over 6 months, your plant is likely suffering from a lack of fertilizer. Apply an appropriate fertilizer (any product indicated for houseplants is a safe choice), and wait to see if your plant's appearance rebounds. 

If your plant's leaves have yellowing patches that often lead to crispy/brown patches, and/or you can see a visible crust of built-up fertilizer salts on the surface of the soil, you've probably used too much fertilizer (or a formula that's too strong or wasn't properly diluted). Remove any affected leaves, and if that 'crust' is present on the soil, scrape it away. Then flush the soil by running water through for several minutes, allow to drain, and repeat 3-4 times to flush excess fertilizer out. Refrain from fertilizing again for a few months. 

 All in all, when yellow leaves appear, my best advice is:

  • Don't panic!
  • Rule out normal causes that are outside of your control.
  • Be thankful your plant can 'communicate' with you through these yellowing leaves so you can make care adjustments and help it live its healthiest life! 

Have a more specific plant question? Visit the Plant Care Help Desk and submit your questions via our google form.