3 Common Causes/Solutions for Yellow Cannabis Leaves in 2023

Green Growth to Yellow Worry: Monitoring Cannabis Problems and Solutions

Don't let yellowing leaves, brown spots, or other issues stress you out. Stay ahead of the game by staying informed about common cannabis problems and their solutions. From calcium deficiency to light burn, heat stress, and more, we'll help you diagnose and fix any issues that come up during your cannabis growth journey.

Monitoring your cannabis growth closely is one of the best ways of learning if there is something wrong. Yellowing leaves are a common warning sign. There are a few factors that can be causing this problem. Once we figure out what is going wrong, we can find a way of solving the issue and getting your cannabis back to full health.

Are Yellow Leaves Natural?

Typically, yellowing leaves in your cannabis plants will indicate that there is some form of stress impacting your crop.  Anything from plant disease, insect pressure (which we will touch on in a later article) to a basic nutrient deficiency and watering practices can be reasons why your plant may begin to show signs of stress such as loss of color.

Although this won’t be a purely diagnostic article, you may find this useful in identifying some potential issues worth investigating further.  Keep in mind that this is not a definitive list and will only cover some of the more common cases of yellowing; so research is key to an accurate diagnosis and treatment of your issue.

During the final weeks of the flowering stage, you can expect that some of your cannabis leaves will yellow and eventually drop.  Outside of the flowering stage, you may want to take this as a sign of potential problems in your crop. Growers should be able to recognize this quickly, so they can sort out the issues before they start to impact yield.

The first step is to identify the cause of the problem. It’s possible that your plants are being affected by one or more of the following issues.

Watering practices

Cannabis plants are sensitive to the amount of water they are being provided. Too much or too little water can easily cause problems. If there is too much moisture in the soil, it can lead to root rot in time. Harmful bacteria or fungus can infect the roots; impacting the growth of your plant or even killing it altogether. Overwatering can also can nutrient lockout in the soil, resulting in nutrient deficiency and yellowing of leaves.

On the other hand, without enough moisture in the soil, the plant may be stunted. When lack of moisture is the core issue, sufficient nutrients and ideal climate won’t be enough to sustain healthy growth patterns.

It’s easy to check if this is the problem. One way is to dig into the soil (away from your plant as to not damage roots, ) and check the soil profile for moisture. It should be damp, but not saturated. For a more scientific measure, you can get a tool to record soil moisture from your local garden center.

Lack of nutrients in the soil

One of the most common reasons why plant leaves turn yellow is because they aren’t able to get adequate nutrients from the soil.  If the soil was not prepped prior to planting, there are still plenty of options to solve these issues.  Nutrients such as Mr. B’s line of products can provide those missing nutrients, and can be found here. You can also learn more about organic vs inorganic fertilizers.

Diagnosing this problem can be tricky, you’ll need to consider the way the yellowing leaves occurred. Here are some of the things you will need to look for:

· Yellowing of the leaves

· Curling or crunching

· Brown spots

Any of these issues could come by themselves or in combination with one another depending on the problem your plant has encountered.

You could go as far as to test the soil or even the plant tissue by sending the media directly to a private lab.  A more thorough lab report will likely ask for your chosen crop and desired yield and provide diagnostics as well as remedial actions to solve the problem and put you closer to your crops’ goal.

pH Imbalance

Another potential problem is the pH level in the soil is too high or low. According to research from North Carolina State University, cannabis can survive a wide range of pH conditions. It can survive in a range of 5 to 7 but it performs best when grown in soil that is between 5.5 and 6.5. A simple pH test will tell you if this is a potential contributing factor for the yellowing in your cannabis plants.

Your solution to this problem will change with the medium you use to grow your plants, but there is an abundance of products specifically designed for correcting pH imbalances for typical grow methods.  How you can correct pH for growing cannabis is a topic we’ll cover in an article of its own.

Growing Environment

When growing indoors, there are some environmental elements that you will need to monitor, these include:

· Type of light the plants are receiving. Like all plants, cannabis requires light to complete the photosynthesis process.  If you suspect there is the problem with your lighting, check out this article which provides more details on the type of grow light your cannabis plant needs.

· Amount of heat. You’ll need to make sure that the lamp is at the right distance from the plants. But not so close that you burn the leaves. Most lights will come with recommendations from the manufacturers.

· Pests. Regularly check your plants for signs of pests or infections. The type of infection will determine how you combat it. For example, fungal problems can be solved by adding mycorrhizal fungi to the soil.

How You Can Stop Yellowing Leaves

Now that we know the most common issues, we can turn our attention to how you can overcome them. In this section, we’ll focus on the most common issues; lack of water, and nutrient issues.

Getting the Right Amount of Water

Container gardening is a bit more controlled when growing cannabis. You can use hoses, meters etc to control the amount of water each plant gets. You can use a drip system, to constantly provide water. If you are growing outdoors, you can use a gauge to find the amount of water the plants are receiving naturally, then increase or decrease the amount you provide accordingly.

Getting the Right Amount of Soil Nutrients

Nutrient deficiency can be one of the most common issues that you face. This may be due to a number of factors, ranging from pH, fertilization history, organic matter in the soil, to your location and the soil type in your area (assuming you grow outdoors).

If your soil is naturally nutrient deficient, you’ll need to be conscious of your fertilization practices going forward.  Using fertilizers that feed the soil in addition to the plant will be best for your long-term success and ability to rectify the issue for future grow seasons.

You’ll want to consider when you apply your fertilizers and how as well. If the NPK mix is wrong, you may be setting yourself up for failure. Don’t forget that you’ll need to add nutrients regularly during the growing season to maintain a healthy growing environment for your plants. At NorCal Nutrients our products have been specifically designed to give cannabis the food they need.

If the cannabis is showing signs of nutrient deficiency. You’ll need to increase the amount of food you are giving them. Do this slowly and monitor the results. After a week or so, they should start to look healthier.

If you have over-fertilized, stop feeding the plants, monitor for stress, and (if outdoors) consider an additional watering early on if there is concern for damage. Again, you’ll need to watch the results closely. Once you start to see the cannabis plants making a recovery, it’s time to return to a healthy feeding routine. The manufacturer should tell you how often and in what quantity to give the nutrients.


Seeing yellowing leaves is often a sign of a problem with your cannabis plant. But it doesn’t mean your crop is going to die. It just means you need to adjust the growing conditions to create an environment where your cannabis can thrive. If you find that nutrient deficiencies are the culprit, consider our tailored nutrient options in our shop.