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Common Issues When Growing Marijuana

Updated November 24, 2022

If you live in an area where it is legal to produce marijuana, then you may choose to grow it instead of buying from a dispensary. This not only gives you complete control over the entire growing process, but also lets you ensure that no chemicals or harsh pesticides are used during growing.

While some strains of cannabis are relatively straightforward to grow, some common problems arise when growing marijuana. These are especially common among beginner growers who lack the experience to avoid the growing issues. Take a closer look at some of the most common issues when growing marijuana, so you will have a better idea of what problems to avoid to ensure plentiful and high-quality yields.

Seeds of Poor Quality

One of the more common problems, especially among beginner growers, is using seeds of poor quality. You may accidentally buy poor quality seeds because they are cheaper. Alternatively, maybe you are a beginner who did not realize your seeds were of less-than-stellar quality until it was too late.

One good indication of poor quality seed is a white shell or a small seed. To maximize your chances of success, opt for the largest, darkest green, and hardest seeds that you can find. You must also follow the proper steps to grow your plant, including germinating the seeds for 72 hours in water and storing it in a dark, dry area.

Nutrient Deficiencies and Nutrient Burn

If you are unfamiliar with growing marijuana, you may not notice that your plants suffer from nutritional deficiencies. You can typically see nutritional deficiencies since the seeds will be light green, thinner, and smaller.

On the other hand of the spectrum, you may overfeed your plants. This would result in the nutrient burn from the fertilizer or nutrients having levels that are too high. Nutrient burn produces brown tips along the leaves’ edges. It can also cause a reduction in growth. If you notice nutrient burn, wait a week or two before feeding the plant again.

Nitrogen Imbalances

In addition to general nutritional deficiencies, some growers will experience issues with nitrogen, in particular. A nitrogen imbalance can lead to a range of problems depending on whether there is too much or too little.

When the marijuana plant does not have enough nitrogen, its leaves will turn yellow, with this process beginning near the bottom of the plant and spreading upward. It can eventually affect the entire plant, and it may spread quickly.

In the case of high nutrient salt levels in the soil, add nitrogen to the soil. Keep in mind that it is sometimes normal for leaves to become yellow in the flowering stages. You can reduce this without impacting the plant’s quality by adding nitrogen to your fertilizer mix as you approach the end of the growing process.

Nitrogen Toxicity

As mentioned, too much nitrogen can be a problem, just like too little nitrogen is. Too much nitrogen in the plants results in nitrogen toxicity. This can lead to the leaves curling into eagle claws. Other symptoms include failing to grow flowers, frequent diseases, frequent pest attacks, stunted growth, and increased susceptibility to frost damage.

To fix nitrogen toxicity, prepare a new growing area or pot with a proper mix of soil, fertilizer, and nitrogen. Transplant the plant into this and use the appropriate quantity of peat moss. You may need to care for the plant for several days to get the desired reduction in nitrogen toxicity. If the leaves have begun falling off and are brown, then it is likely too late for your plant to recover from the nitrogen toxicity.

Ideally, you want to catch nitrogen toxicity as soon as possible, preferably before the plant reaches mature growth. You can also help nitrogen toxicity by using brown organic matter with high carbon levels, like fall leaves or straw. Mix this matter into the soil like you would mulch.

Avoid boosting nutrient levels to overcome nitrogen claw. That can lead to other issues, such as stunted flower production or plant death. You should also avoid over-watering to overcome nitrogen toxicity as it can lead to plant fungal diseases or root rot.

Fertilization Issues

If you are inexperienced with growing cannabis, you may accidentally use too much fertilizer. This can also produce yellowing leaves, leaving you to wonder whether the yellowing is from nitrogen or fertilizer issues. You can tell the difference between the two by flushing your plant using clean water. If the plant improves, you know that the problem was fertilizer. If it does not improve, nitrogen is the problem.

Light Burn

Light burn is a common issue with cannabis plants, and it occurs when you have the plants too close to your lights. You can recognize it as the leave turn yellow and are burnt. Check for the issue by looking at the leaves that are closest to your light.

If you notice light burn, move the lights up between half a foot and foot. You should choose the proximity of the lights to the plants based on the light strength and the growth stage.

Incorrect pH

Many new growers of cannabis also find themselves dealing with incorrect pH levels due to lack of experience. Any variation from the recommended pH levels can cause issues for your marijuana plant. Incorrect pH can lead to the blockage of nutrients so they cannot reach the flowers and leaves of your plant. Most of the signs of improper pH are found in the leaves of the plant, and they can include light brown or yellow spots or tan leaves.

To avoid growing issues due to incorrect pH, be sure to monitor the levels. Check them two times every day and avoid adding too much fertilizer to your plant. If you notice that the pH level is off, try checking the soil as this is the most likely culprit.

In cases when the pH levels are far from desirable, you will need to flush the plant. Always use spring, distilled, or plain water to wash the plant and ensure that water is free from chemicals. Keep monitoring the pH levels as you clean the plant.

Overwatering and Under Watering

Beginner growers are very likely to accidentally overwater or not provide enough water to their marijuana plants. The good news is that either issue is a simple fix, once you notice the problem.

You can recognize that you are under watering your plant if the leaves begin to drop or hang and the growth is slow. Correct that problem by watering the plant more frequently and giving it more water when you do.

You can tell you overwatered the plant if the leaves curl down. The leaves may also seem tight and rigid due to being full of water. The growth can even slow, and your plant may experience root rot. The solution to overwatering your cannabis plant is to water it less frequently. Instead of following your current schedule, decide whether to water the plant based on the dryness of the soil. Water the plant when the soil is dry about an inch deep.


You may also experience mold while growing marijuana, and this can occur on any part of the plant. Whenever you notice mold, dispose of the flowers with the mold. Then, examine your entire plant thoroughly.

Many people find it challenging to spot mold issues on marijuana plants because mold is typically white and fluffy, which is similar to trichomes. If you are unsure whether it is trichomes or fungi, use a magnifying glass.

If you have mold on your marijuana, check the humidity in the growing space. You can prevent mold growth by controlling the moisture. Remember that mold does not need to affect all of the plant parts; it can affect just part of it, but you should always confirm whether that is the case.

Root Problems

Many of the common issues with growing marijuana come from the roots, specifically the root bases. Be on the lookout for the roots curling up, either around the bottom of your cannabis plant or around your root bulb. If either of these types of curling occurs, the roots will likely choke each other. Choked roots result in deficiencies that can lead to the plant’s death.

You should also confirm that the roots are not slimy and do not smell rotten. Either of those issues can indicate that the plant does not have enough oxygen. This lack of oxygen can reduce the end product’s quality and can cause growth problems.

To avoid root problems, make it a point to examine the roots of your marijuana plant carefully at the time of your first transplant. Use this time to confirm that the roots are healthy, free from mold, and do not have too much intertwining. If there is mold in the roots, you will likely have to trim some of the roots back, which can stunt the plant’s growth.

Make sure to transplant your cannabis plant as soon as you can if the roots curl over the edges of your container. This indicates that the plant lacks sufficient room for growth. That can result in reduced production or stunted growth.

Stem Problems

Stem problems are another category of common issues that affect marijuana growth. The stems are crucial as they keep the flowers and plants upright. They also provide water flow and nutrients for the flower. The stems are mostly made of water and fragile. While those who buy marijuana already grown do not necessarily want thick stems, these are a good sign. Thick stems indicate that the plant received enough water and nutrients. That proper nutrition increases the chances of enhanced potency.

On the other hand, if the stems of your plants are thin, this indicates it does not have enough light. You may need to add more lighting or adjust the current lighting system. If you have thin roots, you should also confirm that you trim the plant properly. This will prevent larger leaves from causing shadows on the flowers and blocking their light.

To further avoid stem problems with your marijuana plants, ensure there is enough moving air, as this is required to stimulate the stems. You can do this with a good circulation system with fans.

If a stem is partially broken, you can typically fix it, but you should work to resolve the problem right away. It is possible to tape the broken stem together again. For the best results, however, you should attach a stake to your broken stem. This allows for security and helps the stem continue delivering strength and nutrients to the plant. Fully severed stems, however, are rarely salvageable.

Loose Buds

Sometimes, you may notice that the buds on your marijuana plant are loose. Loose buds are not good as they tend to be harsher when smoked and less potent. This may indicate nitrogen toxicity. However, in most cases, the loose buds are due to improper room temperature or lighting or from nutrient imbalances. It is also possible that loose buds are due to root-based issues or airflow problems.

To encourage your plant to produce tighter buds, opt for lights with orange, red, or yellow light. You can also use reflective material that you can place strategically to ensure the plants get enough light. Keep in mind that light leads to heat, so you must ensure that you control the room’s temperature when you have the lights on. Fans are a good option.


Pests like gnats, spider mites, aphids, or other insects are another common issue when growing marijuana plants. The best way to overcome this is with a solution featuring diluted seaweed. Doing so will increase the plant’s resistance to gnats and other pests that may cause harm. As a bonus, outdoor plants will also get protection from frost damage with this method. You can also try setting up fly tape or fly strips to catch the pests and reduce the damage they can cause.


As you gain experience growing cannabis, you will find it easier to avoid these common issues. It will become second nature to check the pH, position the lights properly, and give your plants the proper amount of water and nutrients. Beginners should stick to growing one or two plants at once while they try to get the hang of it. This minimizes the risk of growth issues by letting you pay closer attention to each plant.

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