March 12, 2021 6 min read

Plants are pretty straightforward with their communication. Is your plant leaning to one direction? That likely means that the most light is coming from that direction, so you should move your plant over there. Is your plant is wilted and slouching? It likely is dehydrated and needs more water. Listening to your plants is one of the best ways to become a better grower. The signs are there, you just need to know why they are there and what to do about it. One sign that pops up more than people would like is yellow leaves. Plants are cultivated for their lush greens and beautiful glow. Yellow leaves detract from that ambiance and can be an eye sore at times. But what does that mean and how can you fix it? Continue reading below to find out.

Why indoor plant leaves turn yellow

Why are the leaves of my plant turning yellow?

There are many reasons as to why your plant’s leaves turn yellow but here are a few that are the most common.
  • Too much/too little water
  • Aging
  • Cold Drafts
  • Root damage/compacted roots
  • Improper soil pH
  • Too much/too little light
  • Viral infection
  • Nutrient deficiency

What are the reasons a plant's leaves would turn yellow?

Extreme Water

Plants need water to survive. They use it to perform photosynthesis which allows them to produce more plant mass and grow. However, just like everything in life, too much can be a bad thing. If you find your plant with yellow leaves, check the soil. Is it dry as a desert or does it look like a mini lake? Neither of these extremes are good for your plant so make sure to keep the soil damp or moist and your plant will be well hydrated.

Aging Plants

As is the case with every living thing in the world, plants eventually have to die. Whether your plant is an annual, biannual or perennial, your plant will eventually die off. Keep good note of the estimated lifespan of your plant as knowing that it is near the end of its lifecycle could save you a lot of time when figuring out why it has yellow leaves.

Cold Drafts Around Plant

Depending on the native origins of your plant, temperature could affect them. If your plant is of a more tropical origin, such as orchids, bamboo or hibiscus, a cold draft may shock the plant and cause its leaves to turn yellow. Make sure you check any nearby windows, doors or vents for any drafts that could be affecting your plant.

Roots are Damaged or Decayed

Roots area a vital part of the plant as they anchor the plant in the ground and collect nutrients for it. If the roots are damaged, the plant will not absorb the correct amount of water and nutrients. On a similar note, if plants outgrow their container, they can have compacted roots. Both of these scenarios are bad for your plant and should be looked into as a possible reason for yellow leaves. Check your plant’s roots by slowly sliding the plant out of the container; healthy roots are white/yellow, compacted roots looked cramped and rotting roots are foul smelling and dark colored.

Improper Soil pH

If you use good fertilizer on your plants, you probably will not have to worry about this. However, it doesn’t hurt to check. Most plants thrive in a soil pH that is a little acidic (6.0-7.0). If soil is outside of a plant’s preferred range, certain nutrients may be lacking. It is important to make sure the pH is correct as it ends up affecting a lot more than you think.

Lack of Light

Plants need light to grow, that is obvious. What isn’t so obvious is how much they need. One way to know the perfect amount of light for you plant is knowing the Daily Light Integral for each plant. Check out our blog on DLI to learn more about it. The yellow side is usually the part that is receiving not enough or too much light. Either move your plant closer to a window, or invest in a grow light for indoor plants.

Viral Infections

Just as humans can contract virus such as COVID-19 or influenza, plants too can become sick from viruses. This is not as simple to notice as the other problems, but it definitely is one of the more important problems to look for. If you leave an infected plant, it could infect neighboring plants and completely ruin your garden. You should always check for an infection so you can cross that off as a possibility.

Nutrient Deficiency

The soil you put your plant in is just as important as the amount of light it receives or the amount of water it has. Plants obtain nutrients such as nitrogen, potassium and phosphorous from the soil through their roots. Check to make sure your plants roots are in a good amount of soil. One other issue might be that your water is too hard. Hard water has lots of calcium in it which can affect the nutrients in the soil. Check that you have not made one of the most common fertilizer mistakes as well.

How can plants recover from having yellow leaves?

Once you have concluded your investigation and have come up with a reasonable explanation for your plant’s leaves turning yellow, the next step is to correct the issue. But how do you do that? Here are some suggestions that we recommend.

Review Your Watering Cycle

  • Restart your watering cycle; place your plant in new dry soil and water until the soil is damp all the way through
  • Check to see the recommended watering frequency for your plant and adhere to that schedule
  • If unsure, you can always poke your finger into the soil up to your first knuckle and water if dry

Why indoor plant leaves turn yellow

Watering your plants on a schedule will help prevent them from getting over or under watered. Sourced via https://pixy.org/247283/

Maintain Aging Plants

  • Trim the dying leaves to a node to promote new growth
  • Surround with newer plants

Move Away from Cold Drafts

  • Move from the location with a draft
  • Mist your plant to increase the humidity

Inspect and Fix Roots

  • If the roots are compacted, trim the compacted ones and repot in a bigger pot
  • If the roots are rotted, try to trim the rotted parts, otherwise it may be time for a new plant

Improper Soil pH

  • Buying a soil pH tester would be a quick and easy way to make sure the yellow leaves are not caused by improper soil pH.
  • A test kit, such as this one on Amazon, can go a long way to maintaining your plant health.
  • Most testing labs can assist in how to get your soil pH back to where it needs to be.

Introduce More Light

  • Move your plant to a place where it can receive less or more light depending on your diagnosis
  • Use a grow light, such as our Aspect, Highlandor Vita grow lights to improve the lighting your plants get.

Viral Infection

  • Quarantine the infected plant as soon as possible
  • Check neighboring plants to make sure that virus has not spread
  • Wash and sterilize any gardening tools you have been using
  • Look for fungicides or other remedies for the specific virus your plant has

Why indoor plant leaves turn yellow

Tobacco etch virus, one of the many plant viruses, affecting a tomato leaf. Sourced via https://www.flickr.com/photos/scotnelson/9416609837/

Nutrient Deficiency

  • Purchasing a soil kit to test your soil would be useful to know which nutrients are needed in the soil
  • Supply your plants with supplements of the nutrients it is lacking
  • Avoid using hard water as the Calcium in it can mess with the nutrients already in the soil

Do yellow leaves turn green again?

Typically, you shouldn’t expect your yellowed leaves to turn back to green even after fixing the issue that turned them yellow initially. In some cases, however, if your leaves turned yellow due to a nutritional deficiency they may become green again when they’ve had time to absorb the proper nutrients! In most cases, though, when the leaves are yellowed due to improper light, watering, or other issues, it is safe to say those leaves won’t return to their ideal state.

Should I cut off yellowed leaves?

Once you’ve determined the cause of your yellowed leaves, you may consider cutting them off. Doing this will keep your plant looking fresh and in the case that the yellowing is caused by a disease, reduce the spread. Removing these leaves will also allow the nutrients you are feeding your plant to be dispersed to healthy leaves more generously, promoting your plant’s beauty. Make sure you understand and resolve the problem that turned the leaves yellow because simply removing them will not prevent more leaves from yellowing, too!

Are yellowed leaves dead?

Yellow leaves are not technically dead but are damaged or dying. Brown, crunchy leaves are generally what we consider to be dead, but as far as the contributions yellow leaves make to the overall plant, we can group them together with dead leaves. Especially because the yellow color can rarely be reversed, these leaves can be considered unsalvageable and therefore equivalent to dead leaves in this way.