If you’ve owned plants for any amount of time, you know there’s more to it than sticking them in a window and occasionally drizzling some water on them. You want to ensure you’re growing happy, healthy, vibrant plants. 

Unfortunately, yellow leaves don't give your home that happy, full of life vibe you were seeking when you brought them home. 

Far from just being unsightly, yellowing plant leaves can indicate a real health problem with your plants. But what? And more importantly, how can you fix it? 

Here are six of the most common causes of yellowing leaves and how to fix it. 

1. Watering Your Plants Too Little — or Too Much

Most yellowing occurs due to water stress — that is to say, you are probably watering your plant too often or too infrequently.

There is such a thing as overwatering your plants, especially if your plant pot doesn't have good drainage. Roots can drown in too much stagnant water, which will kill your plant. Yellow leaves can indicate that your overwatered houseplant has begun to succumb to its soggy conditions. 

On the other hand, your plant might turn yellow and drop leaves to prevent transpiration, the process of water movement through the plant. By killing and dropping its leaves, your plant is trying to cut down on extra foliage to conserve water. Trying this desperately to hold on to water means that your plant is dangerously under-watered. 

If you’re not sure, just look at the plant’s soil. Stick your finger deep into the dirt - at least 2 inches. If the soil is dry, you can bet that it needs more water. 

If the soil is moist, overwatering may be the culprit. Observe the bottom of the planter near the plant’s roots. If the bottom of the planter is wet, or if the drip tray is full of water, you’re probably overwatering your plant. 

Different plants require different water levels, so always research your specific plant before you fill-up, or put away, the watering can. 

2. Routine Plant Aging

Maybe you've had your plant for a while. A very long while, perhaps. Then, all of a sudden, it starts to grow yellow leaves. It could be that your plant is just, well, kind of old. 

Like all living things, an old plant may show signs of aging. Sometimes this aging comes in the form of yellow leaves. 

Don’t despair if you think your plants' yellow leaves are caused by aging, though. A simple trick is to remove these unsightly appendages and restore your plant back to its feisty green self. 

You can remove the yellow leaves from your houseplant through pruning. Cutting off dead leaves doesn’t just make the plant look better; it also allows the plant to focus on growing more, healthier leaves. 

It’s best to prune a little bit at a time. Nip off a yellow leaf when you first see it, rather than letting the whole plant get sick and then cutting it back aggressively. Pruning little and often allows the plant to use its energy on initiating healthy growth, not trying to keep sick leaves holding on. 

3. Lack of Sunlight

All yellow leaves are not created equally. In diagnosing the cause of yellowing leaves, pay close attention to which leaves are turning yellow. 

Are the leaves on only the plant’s bottom layer turning yellow, but the upper leaves look fine?

Or are the leaves on only one side of the plant turning yellow? If so, is this the side that’s facing away from a window?  

If either of these describes your situation, it could be that a lack of sunlight is the culprit.

Usually, yellowing will occur on the plant parts that don't get enough access to the sun. If only the lower or non-window facing parts of your plant are looking yellow, it could lack sunlight. 

To see if this is the problem, move your plant somewhere where it will get more sunlight. If moving the plant isn’t possible, try rotating it every few days to ensure equal access to sunlight. For floor-dwelling plants, consider raising it up off the floor to expose the lower leaves to more sunlight.  

If your plant’s top is becoming overgrown with broad leaves, consider pruning them back to allow more light to hit the bottom leaves - especially true if the upper leaves are not terribly healthy-looking themselves. 

4. Nutritional Imbalance in the Soil

Your plant needs nutrients to grow and thrive. Planting it in nutrient-rich soil will help ensure that your plant stays healthy, and adding more nutrients will only help it become stronger, right? 

Not quite.  

While proper nutrition is essential for every living thing, striking the right nutritional balance is much more important. When it comes to nutrients, too much can be just as harmful as not enough. 

The leaves on your once-happy plant may start to turn yellow if it lacks nutrients. Specifically, nitrogen deficiency is the most common nutritional cause of yellowing leaves. Fortunately, most houseplant-specific fertilizers are nitrogen-fortified for this reason. 

On the other hand, too much calcium is another common cause of yellow leaves. An overabundance of calcium probably won’t come from the soil but from your water supply. 

If you have hard water, it means that there’s a lot of nutrients in your water. These nutrients can wreak havoc on everything from your showerhead to your plant, which could be why your plant leaves are yellow. There are a few things you can do to fix it, from adding water softeners, using water filters, adding a bit of vinegar, or boiling your water. 

Of course, not all houseplants are created equal, and some need a particular nutrient more than their easygoing counterparts. Again, you can more easily diagnose your plant's problems by getting to know its specific care requirements, including nutritional needs.

5. Chilly Drafts

It's not always the soil to blame for yellowing plant leaves. It could be as simple as the placement of your houseplant. 

If you've noticed your plant's leaves starting to yellow and the temperature outside has dropped, it could be that you've placed your greens in a drafty spot. Even a short period of exposure to intense cold can yellow — or brown — the foliage on your once-healthy plant. 

While different plants thrive at different temperatures, almost all of them tolerate a nightly dip in temperature. But sometimes, the temperature dips a little too low or stays that way for too long. 

For most tropical plants, try to avoid letting the temperature drop below 55 degrees. But always research your specific plant to find out what its exact temperature needs are. Keeping a small thermometer near your problem plant is an excellent way to ensure that it’s temperature needs are being met. 

If the yellowing is happening in summer when temperatures are warm day and night, a cold draft could still be to blame — your plant might be right in front of an air conditioner's blast or vent. Luckily, this problem is an easy one to fix. Simply shift your plant out of the way of cold airflow, and it should return to its green normal. 

6. Plant-Based Infection

This yellow-leaf cause may be the hardest to handle. 

Sometimes, your once-happy plant can come down with a viral plant-based infection. It won't just appear as yellow leaves, though. Your plant will probably grow deformed stems and strange foliage, and its flowers might look discolored when they bloom - if they bloom at all.  

These signs indicate that your plant isn't just temporarily unhealthy — it likely has an infection. Worse yet, you can't treat these problems in a houseplant. Unfortunately, the chances are high that you will need to discard your infected plant. 

While it may be tempting to let your plant pal hang around for as long as possible, consider this: your sick plant could infect your other healthy plants. 

If you’re just too attached to throw him in the trash, and the very least, move the sick plant to its own room where it will be kept well away from the rest of your indoor jungle. Water and handle your sick plant last (if at all), to avoid spreading the infection via contaminated tools and hands. And just like a sick person, always wash your hands after touching or watering your sick plant.  

Continue Cultivating Happy Plants

Yellow leaves are ugly, but they’re not the end!

They don't necessarily signal the end of your plant’s life, but rather sign that something you’re doing just isn’t working correctly.

Reassess the type of plant you have, and it’s water, sunlight, temperature, and nutritional needs. Then, see what you can change to give your plant what it needs to be healthy.  

Often, a simple tweak or two to your care regime is all that’s needed to encourage healthy, green growth for years to come. 

Whether you're new to the houseplant world or looking to add to your indoor greenhouse, we can partner you with the perfect foliage piece. Check out our inventory of plants, which we ship across the country.