Troubleshooting common cannabis plant problems

Cannabis plants are resilient. The plant grows successfully all over the globe in many different climates—it’s called “weed” for a reason. 

But many problems can arise when growing cannabis, both indoors and outdoors. Bad weather, bugs, nutrient deficiencies, improper watering, and many other issues can pop up. 

What’s wrong with my weed plant?

Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube.

Many issues can arise when growing weed: discoloration of leaves is usually a sign of nutrient deficiency; tiny spots or webbing can mean a bug infestation; stunted growth can be a root problem.

Check out these articles on specific topics on how to troubleshoot issues with marijuana plants:

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Marijuana plant nutrient deficiencies

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Identifying bud rot, mold, and root rot on marijuana plants

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How to get rid of pests and little bugs in weed plants

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How to keep animals out of your outdoor cannabis garden

Common mistakes when growing marijuana

Here are some common mistakes newbie weed growers make.

Overwatering cannabis plants

New growers are often guilty of giving their new weed plants too much love. As we’ve mentioned before, it’s called weed for a reason—a lot of times the answer is to just let the plant be.

This can manifest in overwatering. A new grower may overthink watering and water too much. 

But the drying out of soil is important too—that’s how roots pull oxygen out of soil and into the plant. Additionally, standing water can stay in soil and cause root rot if not given enough time to dry out.

Remember to only water a plant if the soil is dry 1-2 inches down. Check out our guide on watering for more info.  

Too many nutrients

Similar to overwatering, beginning growers also have the tendency to give plants too many nutrients. A common misconception is that more nutrients equals bigger plants, so just keep adding more and more!

This is a bad idea and will quickly lead to nutrient lockout or other nutrient deficiencies. Nutrient lockout occurs when a weed plant can’t take in any more nutrients. 

A weed plant needs the correct balance of nutrients for it to grow properly and be healthy. If anything, err of the side of too little nutrients—it’s a lot harder to correct a plant with too many nutrients than to add more. Keep in mind that organic nutrients are a little more forgiving. 

Also, keep an eye on the pH of water you use on your weed plants. This overlooked aspect can quickly lead to big problems.

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Common problems to look out for when growing weed

Of course there are many problems that can arise when growing weed that should be fixed quickly. Weed plants are rather responsive, meaning they will show signs of distress if they aren’t getting the proper nutrients, have a bug infestation, or some other issue.

Check your cannabis plants regularly for issues. A good time to do this is when pruning, because you’ll be up close and personal with your plants. 

Look at the main stalk of the plant. Stunted growth can be a sign of roots being bound or some other root issue. If one plant is considerably smaller than others or if you’ve been growing it for a while and it seems too small, it could have root issues.

Look for and remove dead or yellowing leaves, and weak or withering branches. If plants are flowering, look for bud rot and mold.

Inspect under fan leaves, as that’s where some bugs live—such as spider mites—and check where the stalk comes out of the soil, as some bugs live there too—in particular, root aphids. 

Cannabis plant leaves should be a dark, vibrant green. Yellowing, discoloration, or spots on leaves are another big giveaway that your plant is sickly.

Check out our guide on nutrient deficiencies for more info.

Johanna Silver and Trevor Hennings contributed to this article.