How to Solve 99% of Cannabis Plant Problems

Created by
Added 18 January 2022

Smoking cannabis is fun, but growing it is just as tricky. You are bound to run into various problems while growing cannabis — and this happens to every grower — it’s just a norm with it. 

You’re going to face minor problems growing any other crop — tomatoes, potatoes, chilies, etc., but you can’t compare any of them to cannabis, so you take special care of your priced plants.

A small problem makes you lose sleep, especially if you’re a beginner, but it’s also true that you can solve most cannabis problems if you take a few steps. 

In other words, 99% of your cannabis problems can be solved with a few rules. 

What are they? 

This article shares some insights on solving almost all cannabis growing problems you may face.

1. Check the pH to Diagnose Nutrient Problems

Check the pH

Nutrition is one aspect that can cause various problems. And often, the pH level of the nutrient is the main culprit.

If the pH is off even by a few decimals, your cannabis plant can exhibit signs of nutrient deficiency because the plant cannot absorb nutrients properly due to improper pH levels.

For example, if the pH is too low, your plant may suffer magnesium deficiency. 

So, if you notice any signs of nutrient deficiency or nutrient burn, we recommend looking at the pH balance first. Invest in a high-quality pH pen and read about the pH required for your specific growing medium

For hydroponic growers, the ideal pH range is from 5.5 to 6.5, while soil growers need to maintain it between 6 to 7.

Adjust the pH by flushing the growing medium and nutrient solution if the pH is off. You can even use pH balancing solutions if you don’t want to go through the hassle of flushing the nutrient solution.

A pH imbalance may not always be the case for nutrient deficiency or burn. Therefore, check the pH first, but you need to verify your nutrient solution if the pH is ideal. 

In addition, remember that the pH of the nutrient solution will fluctuate over time. This is because cannabis consumes some nutrients faster than others, leading to wrong nutrient ratios after a few days. 

It’s best to change your nutrient solution at least once a week to ensure optimum nutrient ratios. 

Next, learn what nutrients your cannabis plant needs at different stages of growth. For example, the NPK ratios for the growth stage are:

  • Vegetative stage: 1:1:1
  • Mid-bloom stage: 1:3:2
  • Late flowering stage: 0:3:3

You can even use readily available nutrient solutions for your cannabis plant. They are formulated specifically for each growing stage and environment, preventing guesswork.  

2. Verify Your Watering Habits and Root Health

Root health

Your cannabis plant gets most of its food from the roots, whether it’s water, nutrients, or oxygen. Unhealthy roots often transfer the illness to the entire plant, so it’s imperative to understand root rot symptoms. 

Some of the most common symptoms of root issues include the following:

  • Wilting or drooping of the leaves
  • Yellowing or spotting of the leaves
  • Brown edges on the leaves
  • Symptoms akin to nutrient deficiency and more

Typically, these root problems occur due to improper watering of the plant. So, to solve problems with your roots, ensure you’re watering the plants appropriately.

Below are more details on how to determine improper watering for your cannabis plant, along with the signs of root rot.

Overwatered cannabis plant signs:

  • Drooping leaves or plants
  • Symptoms of nutrient deficiency despite the nutrient solution and pH being ideal
  • Brown spots, yellowing, or bleaching on the leaves
  • Stunted plant growth
  • Green algae growth on the topsoil
  • Fungus gnat infestation on the soil

Underwatered cannabis plant signs:

  • Wilted or droopy plants
  • Symptoms akin to nutrient deficiency
  • Dark-green colored leaves
  • Stunted growth
  • Dry or dusty growing medium
  • Plant feeling too light for its size

Symptoms of root rot:

  • Mushy or spongy roots
  • Musky odor from the roots or under the growing medium
  • Browning of the roots

If your plant resembles any of the above traits, you must immediately fix it. Here’s how you do that:

  • Ensure your growing medium is ideal for your cannabis plant. For example, avoid using dirt from your garden or low-quality potting mixes; instead, use super soil, high-quality potting soil, coco, or hydro that ensure healthy root growth.
  • Make sure you are watering your plant properly (neither underwatering nor overwatering. To do this, ensure the water drains freely from your growing medium to avoid soaking it altogether. 
  • Let the roots breathe. Your plant's medium should be loose, not dense, to encourage unrestricted airflow. Add perlite to your soil if it’s too dense. If using a hydroponic setup, air stones that oxygenate the water will do the trick.
  • On the other hand, if you are using a non-standard growing medium, understand how to take care of it thoroughly. Use manufacturer recommendations or join internet forums to learn more.
  • Never let your cannabis plant dry out or sit in stagnant water. The roots need a mix of oxygen and moisture to thrive.

3. Check the Environment

Check environment

If your cannabis plant is unhealthy, water, pH, and nutrients are likely culprits. However, if that’s not the case, you need to check the growing environment.

An ideal growing environment is vital for a healthy plant — improper temperature or humidity levels can significantly affect your cannabis plant.

For instance, if your grow room is too hot or has low humidity, your plant may experience symptoms like a nutrient burn because arid, hot conditions make your plant drink more water than usual for transpiration.

Your cannabis plant may also start wilting or turn brown if your grow lights are too hot.

On the other hand, improper humidity can cause stunted growth, white powdery mold on the leaves and buds, or bud rot. These can be pretty difficult to fix.

Follow these tips to solve these environmental-related problems:

  • Ensure the temperature is between 75°F to 80°F during the day and 75°F during the night.
  • Adjust the humidity according to its growth stage, such as:
    • Clone plants: 70% RH humidity
    • Vegetative stage: 40% to 60% RH
    • Flowering stage: 40% to 50% RH (to increase resin production)
  • Invest in high-quality temperature and humidity monitors.
  • If you need to change the conditions artificially, we recommend using humidifiers.
  • Avoid pointing fans directly towards the plant; instead, point them to a wall to circulate the air indirectly.
  • Ensure proper ventilation of your grow room to let the stale air out.
  • Pump up the CO2; the ideal amount should be around 1000 to 1500 ppm in your grow room for healthy growth and bud development.

4. Identify Light Issues

Identify light issues

Cannabis, like any other plant, loves light. The plant grows faster when there’s enough light for it to absorb. But your light may be an issue sometimes.

If your cannabis plant is exhibiting stunted growth, not drinking enough water, or any other symptoms, but you can’t trace it back to any of the issues listed above, then light is most probably the reason.

So, check your grow lights. Cannabis plants need at least 100W lights to grow correctly, and the more the merrier. But, don’t overdo it because too much light can also stress the plants. It can also give your cannabis plant a light burn, causing bleaching or yellowing of the leaves. Fresh clones and young plants are especially prone to light burns.

Typically, HPS lights are prone to burn the leaves if they are positioned too close to plants. To avoid this, simply place the back of your palm under the light, next to your plant. If your hand starts feeling warm after 10 to 15 seconds, the light is too close or too warm. 

Each light is different, so we can’t recommend the height. Instead, go with manufacturer recommendations. 

5. Look for Pests

Pest issues

Lastly, look for pests around your plant. Pests are notorious for hiding and causing all kinds of problems from nutrient deficiency, mold, spots on the leaves, wilting, and a lot more.

The most common cannabis pests are spider mites (the worst), aphids, fungus gnats, aphids, slugs, caterpillars, and thrips. 

Identify the bug first — look under the leaves and on the soil. Then, use the right pesticide to eliminate the bugs. 

The best pesticides are organic ones as they don’t harm the plant but eliminate the bugs; never use chemical pesticides as they are bad for the plant (and the environment).

We recommend using pesticides like neem oil, spinosad, horticultural oils, alcohol + water solution, and BT sprays, etc. 

Apart from that, you can even use predatory bugs for hunting these pests. Here, ladybugs and lacewings are your best friends.

Summary: How to Solve 99% of Cannabis Plant Problems

Don’t freak out when you notice issues! Calm down. The way you react determines your yield.

So, first, identify the symptoms and start the process of elimination to figure out the root of the cause. And then search for the solution. 

That’s all it takes to solve almost any problems with your cannabis plant. 



Be the first to comment it