Cannabis plants may not be able to vocalize their distress, but they can certainly send signals to indicate that something is wrong. One such signal is the appearance of curly or clawing leaves. If you notice this happening in your grow-op, it’s important to take action promptly to avoid negatively impacting the quality of your final product.

In this guide, we will explore the various reasons why this phenomenon occurs and provide you with helpful tips on how to prevent it from affecting your cannabis strains.

Overwatering

Overwatering is one of the biggest threats to the well-being of any cannabis plant. When plants receive too much water, their root systems cannot absorb the surplus and cause oxygen deprivation. This can affect both adult and germinating plants, as they rely on oxygen for nutrients and growth. The roots become unable to respire effectively, leading to wilting and other problems such as yellowing of leaves or drooping stems. Even if this problem is solved before it reaches such an extreme point through careful monitoring of water levels, it can still lead to slower growth and development.

Not only does overwatering have negative effects on plant health, but it also upsets a balanced soil ecosystem. Excess water will wash away beneficial microbes that aid in nutrient uptake as well as encourage genetic mutations which attack the root system from within.

Pythium Root Rot is particularly problematic in this situation – whilst usually harmless in small numbers, these foamy white mushrooms are far more aggressive in moist environments where stressed-out roots provide an ideal breeding ground for the parasite. Luckily this issue is stress-free to prevent but must be monitored closely during development stages to ensure limited harm occurs during flowering periods.

How To Fix It

Overwatering during flowering can cause the leaves of cannabis plants to “canoe” or curl upwards, which can lead to reduced growth and yield. Here are some steps you can take to fix this issue:

1. Reduce watering frequency: This is the most important step in fixing overwatering. Watering frequency should be reduced to once every 2-3 days and the soil should be allowed to dry out between waterings.
2. Check soil drainage: Make sure that your soil is well-draining so that water does not sit in the soil for too long. You may need to add perlite or sand to improve the soil’s drainage.
3. Waterless: When you do water, water less each time, so that the soil does not become too saturated. A good rule of thumb is to water until you see about 10% runoff, then stop.
4. Improve airflow: Good airflow is important for preventing overwatering, as it allows the soil to dry out more quickly. Make sure your plants are not crowded and that there is plenty of air circulating around them.
5. Check root health: If the root system is damaged, it can be difficult for the plant to take up water properly, leading to overwatering. You can check the root system by carefully removing the plant from its pot and examining the roots. If they are healthy, they should be white and firm. If they are black and mushy, they have likely been damaged by overwatering.

By following these steps, you should be able to fix the issue of canoeing leaves caused by overwatering and help your cannabis plants thrive during flowering.

Overfertilization

Overfertilization is a common issue among inexperienced cannabis cultivators. Too much nitrogen, phosphorus, or potassium in the plant’s nutrient deficiency can cause serious damage to the leaves. When excessive amounts of nitrogen are used in the vegetative stage, the characteristic symptom is clawing – where leaves twist and curl inwards due to a lack of photosynthetic material between the veins. If left untreated, the leaves may canoe – pointed along the edges instead of being flat as usual.

The flowering stage presents similar issues when it comes to overfertilization; too much phosphorus or potassium can also stunt growth and create other issues such as chlorosis – a process where yellowing starts at the margins of leaves and progresses inward. This is usually accompanied by leaf curling and scorching, which limits the health and yield of your buds by reducing their ability to absorb light and CO2 from their environment. Such cases should be avoided for any crop’s well-being.

How To Fix It

Here are some steps you can take to fix this issue:

1. Flush the soil: Flushing the soil with plain water can help to remove excess nutrients and salts that may have accumulated due to overfertilization. Water the plants heavily until the runoff water is clear. Repeat this process several times to ensure that all excess nutrients have been flushed from the soil.
2. Reduce fertilizer application: Reduce the amount of excess fertilizer you are using or stop using it altogether. Overfertilization can lead to a buildup of salts in the soil that can damage the roots and leave the plant growth unable to absorb water properly.
3. Check soil pH: Overfertilization can cause the soil pH level to become too high or too low, making it difficult for the entire plant to absorb nutrients properly. Check the pH of your soil and adjust it if necessary to ensure that it is within the proper range for cannabis (6.0-7.0).
4. Provide proper light: Overfertilization can cause the leaves to become yellow and curled, which can be mistaken for a light deficiency. Make sure your plants are getting enough light and adjust the lighting if necessary.

Temperatures Are Too Hot

Heat stress is one of the most common causes of leaf curl and damage to cannabis strains. This type of environmental stress can occur as a result of either indoor or outdoor temperatures that are too high. If you start to notice that your cannabis leaves are starting to curl, turn yellow, or display brown sludge fringing then it’s likely that the temperatures in which they’re growing in are too hot for them. Temperatures above 30°C can be dangerous for your outdoor plants and if combined with low relative humidity (RH) levels it can quickly spiral into a problem.

How To Fix it

Here are some steps you can take to fix this issue:

1. Lower the temperature: Make sure that the temperature in your grows room is within the proper range for cannabis, which is between 68-77°F (20-25°C). If the temperature is too high, consider using fans or air conditioning to lower it.
2. Improve airflow: Good airflow is important for preventing high temperatures, as it helps to circulate cool air throughout the grow room. Make sure your heat-stressed plants are not crowded and that there is plenty of air circulating around them.
3. Check humidity levels: High temperatures can cause humidity levels to rise, which can be harmful to cannabis plants. Make sure the humidity levels are within the proper range, which is between 40-60%.
4. Avoid direct light: If the temperature is high, it is important to avoid exposing your healthy plants to direct light, as this will only make the temperature rise further. Make sure your marijuana plants are not positioned too close to lights or windows where they might receive direct sunlight.
5. Provide shade: If the temperature is too high, consider providing shade for your plants. You can use shade cloth or other materials to reduce the amount of light and heat that reaches your plants.

By following these steps, you should be able to fix the issue of curly leaves caused by high temperatures and help your cannabis plants thrive during flowering.

Temperatures Are Too Cold

Cold temperatures can cause adverse effects on the growth of cannabis plants. When temperatures drop below 10°C, the leaves of the weed plant start to curl and discolor. The buds will become loose and leafy and will be more prone to Botrytis or bud rot, especially when coupled with a high relative humidity level. In addition, cooler nighttime temperatures late in bloom will not result in desired purple hues being prominent in buds due to prolonged exposure to cold temperatures.

How To Fix It

Here are some steps you can take to fix this issue:

1. Raise the temperature: Make sure that the temperature in your grow room is within the proper range for cannabis, which is between 68-77°F (20-25°C). If the temperature is too low, consider using heating elements or a grow room heater to raise it.
2. Improve insulation: Good insulation is important for preventing low temperatures, as it helps to maintain a consistent temperature in the grow room. Make sure your grow room is properly insulated to keep the temperature from fluctuating.
3. Check humidity levels: Low temperatures can cause the humidity levels to drop, which can be harmful to cannabis plants. Make sure the humidity levels are within the proper range, which is between 40-60%.
4. Provide additional light: If the temperature is too low, consider providing additional light for your plants. This can help to raise the temperature and improve growth.
5. Use a thermometer: Keep a thermometer in the grow room to monitor the temperature and make adjustments as needed. This will help you to keep the temperature within the proper range and prevent curling leaves from occurring.

By following these steps, you should be able to fix the issue of canoeing leaves caused by low temperatures and help your cannabis plants thrive during flowering.