Whether it’s excessive humidity or a temperature that’s too high, climate fluctuations can have a strong effect on your marijuana plants. Growing areas have a natural tendency to be high in humidity since moisture is let off from marijuana plants. A grow room that is too hot will also lead to issues. Take action to ensure that your plants don’t experience long-term, negative effects.
In this article we will discuss:
Signs of a Climate Problem
You will know you have a temperature problem when your marijuana plants begin showing signs of stress, specifically on the leaves nearest the source of light (or heat if it’s a different source). These leaves will begin to yellow, and brown spots or burns will start popping up.
Download my free marijuana grow guide at this link for more about climate problems
Humidity determines how much or how little water your marijuana plants are going to allow to evaporate. If the humidity is too low, the evaporation pressure will be higher, meaning your plant is able to absorb water and nutrients at a faster rate. If this rate gets to be too much, however, your plant will close its stomata so that it doesn’t lose all of its water and become dehydrated. At this point plant growth will have slowed, meaning it is crucial for you to maintain the perfect humidity level.
How to Fix a Climate Problem
When it comes to humidity, a dehumidifier is the best way to solve the issue in a closed system. Dehumidifiers are equipped with cold tubing that simply condense air moisture, therefore decreasing the humidity level of the room. They could have the opposite effect when it comes to heat, however since the machine itself gives off some heat and, therefore, could lead to your grow room actually being too hot. One simple way of avoiding this is by adding some air vent tubing to the spot that the dehumidifier’s exhaust comes from. This will direct the heat to a place that doesn’t increase your grow room temperature.
If heat is the original problem in your grow room, you should make sure to cool it down before it turns into a health problem for your plants. Adding ventilation is a good way to decrease the level of heat, as is placing an air conditioner into your grow room set up.
Another way of dealing with the problem is, sometime before the flowering phase of your plants’ life cycle begins, install an air cooler. It evaporates water, therefore making the overall temperature of the room cooler. It doesn’t add a significant amount of moisture, so humidity will not be out of control, and have a high level of efficiency during your plants’ vegetative stage of growth. Make sure you don’t use it while the flowering stage is occurring, however, as it could make the level of moisture too high for your plants to be content.
To reduce excess heat, remove any equipment that produces heat and doesn’t need to be in the grow room. Some examples of this are large pumps or light ballasts.
If your plants are grown in a hydroponic growing system, you can change the temperature of the plants themselves in contrast to the exterior temperature. This is done simply by lowering the temperature of the water your plants are growing in. Keep the water cool by using aquarium water coolers, which handle this process automatically. A good rule of thumb is to reduce the water temperature to somewhere in the 60s (between 15 and 20 degrees Celcius) if the air temperature is somewhere in the 80s (between 27 and 30 degrees Celcius).
Preventative measures are the best way to keep your grow room temperature from becoming a problem. You can get lights that are either air or water-cooled, therefore keeping the heat produced out of your grow room. It basically just uses tubing to redirect the heat produced by the lamps outside so the same amount of heat can be produced without actually affecting your grow room.
Marijuana Plant Symptoms
- Leaf edges curl upwards
- Yellowing leaves
- Brown spots on leaves
- Leaves nearest light or heat affected
- Leaf burns
- Slowed growth
In case you have significant differences in temperature between nighttime and daytime, you can simply reverse the lighting order. Keep the lights on through the night (making the cold nights a bit warmer) and keep them off during the day, therefore cooling things off in the afternoon heat. You will, therefore, achieve a more constant, ideal temperature level for your plants.
Grow Room Temperature Problems
What to do when your marijuana grow room is very humid? The grow space will naturally be humid because the marijuana plants emanate moisture that collects in the garden space. To get rid of that moisture, the easiest thing you can do is ventilate the room and replace the moisture with drier air.
For gardens that are closed systems, a dehumidifier must be used. Dehumidifiers have cold tubing that will condense the moisture in the air and make it less humid. Of course, they do release heat and can make the grow space too hot if you’re not careful. To avoid overheating, just affix some air vent tubing to the dehumidifier’s exhaust so that the heat is pointed outside the grow space.
If the room is both hot and humid, an air conditioner could work toward removing the moisture while cooling the garden. Make sure to download my free marijuana grow bible at this link and learn how to create perfect conditions in your marijuana grow room.
What to do when your marijuana room is too hot? There are plenty of ways to cool down an overheated grow room. See what suits you best:
- It can be ventilated to remove the heat.
- An air conditioner can replace the hot air with cool air.
- Prior to flowering, an air cooler that evaporates water to lower the temperature can be beneficial. These coolers won’t add too much moisture to the air and are ideal and extremely efficient during vegetative growth. They are, however, not good for plants in the flowering stage because they create too much moisture.
- If the temperature drops drastically at night, you could solve the heat issues by running the garden’s lights at night instead of the day.
- Hydroponically-grown plants can shift temperatures based on how hot or cold the water is. You can keep the plants cool even if it’s technically hot outside. If the room temperature is somewhere in the 80’s (27-30*C), try to keep the water temperature in the 60’s (15-20*C). Growers can install aquarium water coolers to keep the water cool automatically.
- Any heat producing equipment should be taken out of the grow room is at all possible (e.g. light ballasts and large pumps).
- Avoiding heat starts from the beginning. Take preventative measures to ensure that heat will not be an issue with your crop. Air- or water-cooled lights keep the lamp’s heat from entering the garden. A series of tubes takes the heat from the lamps to the outside without affecting the temperature in the grow room itself.
Remember that plants with strong genetics have less chance of getting sick and are less vulnerable for environmental stresses. So make sure to buy marijuana seeds from a trusted seed bank.
FAQ About Climate Problems
Some of the most common climate problems when growing weed plants are either excessive temperature or humidity.
Naturally, the growing room should be humid as the pot plants emanate moisture that gathers in the garden space. The best way to do is to ventilate the area and cover the damp with drier air, and get rid of the damp.
An overheated growing room will trigger the plants to experience a variety of other problems. Firstly, burning of nutrients may occur at high temperatures by enhanced water transpiration. Mildew can also occur, especially when the room is too humid.
Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible
The founder of I Love Growing Marijuana, Robert Bergman, is a marijuana growing expert that enjoys sharing his knowledge with the world. He combines years of experience, ranging from small-scale grows to massive operations, with a passion for growing. His articles include tutorials on growing... [read more]