Introducing troubleshooting your Cannabis plants

Cannabis plant troubleshooting

Cannabis plants have a high level of resilience and plants grow successfully in a wide variety of climates all across the globe. However, growing cannabis isn’t without problems.

Growing cannabis, indoors or outdoors, can pose many challenges. The environment can be a problem because of bug infestations, nutrient deficiencies, and improper irrigation.

When growing cannabis, many issues can occur; discoloured leaves can indicate nutrient deficiencies, tiny spots or webbings on the leaves can indicate a bug infestation and stunted growth can indicate root problems.

Newbie Cannabis Growers Mistakes

It’s common for new growers to become overindulgent in their cannabis plants.  To a certain extent, it is often best to just let the plant be – that is why cannabis is often referred to as weed.

The culprit is often overwatering, which leads to a damaged plant.  It is a common mistake for new growers to overwater their plants.

It is also necessary for the soil to dry out to allow the roots to draw oxygen from the earth.  Furthermore, if not dried out, standing water can cause root rot and fungal infection.

Plants should only be watered when the soil feels dry about one to two inches below the surface and make sure that you have proper drainage so that the plant isn’t sitting in water. If possible, lift your plant to gauge how much water is in the soil by the weight of the pot.

Signs of Overwatering

-drooping leaves (watch for this, especially if you have just watered)

-yellowing of the leaves or brown spots on the leaves

-leaves will curl

-you may also notice small black flies buzzing around that are attracted to wet, boggy soil.

Signs of Underwatering

-The leaves will droop but will perk up once you water the plant

-dry, paper-like leaves

-soil will be dry and may appear dusty

-if your soil is dry deeper than 1 to 2 from the surface, it’s time to water.

NOTE: the health of the root of your plant will determine the health of your plant.

Overfeeding and Nutrients

Just as new growers tend to overwater their plants, they may also overfeed them with nutrients.  People often believe that the more nutrients you add, the bigger the plants will get! Nutrient lockout is when a plant cannot absorb nutrients from it’s grow medium. This can happen because the pH of your grow medium is out of wack, often due to feeding your plant too many nutrients.  The plant can no longer absorb the nutrients it needs and may die if the levels aren’t corrected.

For cannabis plants to grow properly and be healthy, they need the proper balance of nutrients. When it comes to nutrients, adding too many will make it challenging to correct the nutrients to the proper level to ensure the plants thrive. In addition, pay attention to the pH level of the water you intend to use for your cannabis plant. Ignoring this aspect can result in serious problems.

Stunted Growth

There are a number of problems that you can run into when growing cannabis that should be noted and addressed right away. Symptoms of distress will appear in cannabis plants if they do not receive the proper amount of nutrients, have a bug infestation, or are otherwise stressed.

By regularly checking for problems, you can keep your cannabis plants healthy. During pruning, you will have the opportunity to observe your plants up close.  Check out the main stem of the plant. In many cases stunted growth is an indication that roots are bound or some other problem with the roots exist. If you have been growing the plant a long time and it seems too tiny or drastically smaller than the others, the roots may be the cause.

Dead, weak or yellowing leaves and weak or withering branches need to be removed.  Look for mold on buds if the plants are flowering. The underside of leaves is particularly important to examine since some bugs reside there, including spider mites. Another place to examine is the point where the stalk emerges from the ground as this is where you might find root aphids.


Bugs can be a problem when growing cannabis but can be kept to a minimum by having good circulation around your plants and good light. Growing plant such as garlic or other fragrant plants may deter bugs but if that doesn’t work, DIY solutions such as homemade insecticidal soap can help or there are pesticides on the market but use the sparingly as they may be toxic.

Wet soil attracts fungus gnats, a tiny black fly whose larvae burrow into soil and attack plants’ roots. The sticky secretions left by gnats attract Insects like ants which feed on the cannabis plant nutrients. Using Fly paper near the soil will help deter fungus gnats. Aphids cause leaves to yellow and wilt because they leave shiny spots. Ladybugs get rid of aphids effectively. Spider mites consume chlorophyll on leaves, leaving it with small white spots and fine webbing. To get rid of them, you can use tomato leaves steeped in water or garlic and onion steeped in water. Look on the underside of leaves to find these pets and make sure to get rid of them as they can stunt plant growth. In order to get rid of them, increase air circulation. To dislodge the mites, spray the underside and top of the leaves with insecticidal soap or water.

pH Levels

pH Level needs to be in balance and should be checked at least every 2 days. The optimal pH balance is between 6.0 and 7.0. If your pH is too high, your plant may show signs of stress such as yellowing or have dry leaves which start to fall off. Too low and your plant will experience slow growth. You can try adding lime to the soil if the pH is too low.  If the pH is too high and your leaves are burned, remove any dead leaves and make sure your plant has plenty of circulation. You can try to flush your plant with clean water to bring the pH level within range or adding sulphur will decrease pH levels.

 A marijuana plant’s leaves should have a dark, vibrant green colour. So, if you see that your leaves are yellowing or have spots on them, you probably need to investigate and address the issue to ensure your plant thrives.

To learn more about how to grow the best cannabis plants, see our article on the best soils and nutrients.

Tip: At Grow and Share and Toke and Talk, you can save money while acquiring new strains, meet like-minded cannabis enthusiasts, learn more about the world of cannabis, share pictures of your favorite strains, ask questions and create private groups.