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.
Check out these articles on specific topics on how to troubleshoot issues with marijuana plants:
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
Overwatering cannabis plants
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.
Look for and remove dead or yellowing leaves, and weak or withering branches. If plants are flowering, look for bud rot and mold.
What’s wrong with my weed plant?
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.
One of the most important things that every cannabis cultivator can do is a daily visual inspection. It is likely that many cannabis cultivators stare at their plants probably more than they should, however, many make the mistake of not inspecting their plants often enough. Whether it’s bugs, temperature, disease, some type of equipment malfunction, or nutrient deficiencies, it does not take long for a cannabis garden to be ruined, which is why constant monitoring and early intervention is key.
Many products exist that can be added to water and fed to cannabis plants to fix a nitrogen deficiency problem. Make sure to proceed with caution when it comes to nitrogen. A little goes a long way and too much nitrogen can quickly kill a cannabis plant. As with all nutrient deficiency adjustments, try to add additional nitrogen to the feeding schedule of one plant and see how it reacts. If it seems to help, then apply the additional nitrogen to the feeding schedule of the other plants.
Early Intervention & Frequent Monitoring
As previously mentioned, the cannabis plant will require different levels of nutrients depending on where it’s at in the growth cycle. Some deficiencies in cannabis plants are more common during the vegetative phase compared to the flowering phase.
Even if other factors can be confidently ruled out, it is still possible that it’s not the nutrients themselves that are the cause of the issue. It’s quite possible that the cultivator is feeding their plants the right amount of nutrients yet the marijuana plants are not absorbing them properly due to one or more reasons.
Common Nutrient Deficiencies During The Vegetative Stage
In addition to the previously mentioned types of nutrient deficiencies, which can all occur during the flowering phase, several other types of nutrient deficiencies are common during the flowering phase. When a cannabis plant is flowering it requires more nutrients, which is why so many more types of nutrient deficiencies occur during this phase of the plant’s growth cycle.
First shows on the large, older leaves at the bottom of your plant. The symptoms manifest in leaves that turn dark green and in many cases, get brownish or blueish patches.
Yellow Leaves And Discoloring
Nitrogen deficiency begins with the loss of color in the tip of the leaf. This loss of color will begin to move inward, leaving the leaf completely pale. The leaf will then start to brown and wrinkle, until it finally falls off the plant.
Dark Or Brown Leaves
Rinse your plant Thoroughly. Ensure your pH is right.
1/Rinse your soil.
2/PH all your water before watering.
3/Do not use excess nutrients.
4/Make sure you’re using a fan.
5/If possible, keep your humidity levels relatively low.
6/(I use) Neem oil with a touch of vinegar to correct my pest and fungal problems.
Spoonful of Neem oil and a spoonful of vinegar to a quart of water, shake vigorously before using.