Climate fluctuation can have a strong impact on marijuana plants. For outdoor growers, there’s little to be done about them beyond choosing outdoor marijuana seeds that have a track record of success in their climate zones. For indoor growers, creating an optimal climate requires work, but it’s possible just about anywhere.
Creating an optimal indoor climate requires more than just ensuring that the grow room stays within the right temperature range. Everything from humidity to light intensity can also affect how marijuana grows.
Temperature is one of the most important environmental factors influencing indoor growers’ plant health and yields. It doesn’t just affect plant growth, but also other climate factors like humidity and air quality. The hotter the air is in the room, the more water vapor it can hold and the more likely growers are to experience problems with bud rot, mold, and mildew.
The optimal temperature for i49 marijuana plants varies depending on their life stage. For seedlings, it’s between 68 and 77 degrees Fahrenheit. Plants in the vegetative stage do best when temperatures are kept within 68 and 77 degrees Fahrenheit during the day, although growers can set the thermostat a little lower at night. During the flowering stage, it’s best to keep the temperature under 75 degrees.
Any marijuana plants grown from natural pot seeds can sustain heat damage if the temperatures are too high. Symptoms include yellowing leaves, curled leaf edges, and burns. If the temperatures drop too low, the plants may wilt, experience slowed growth, or even die.
Fixing problems with low temperatures in a grow room is relatively easy. Set the thermostat for the room to a timer to turn the heat down at night to mimic the plants’ natural environment and install fans to ensure adequate airflow. Fixing high temperatures is a little more difficult, which is a shame because it’s a more common problem.
Those who are concerned about energy use can reduce temperatures a little by removing heat-producing equipment from the grow room, including light ballasts and large pumps. In hot climates, that’s not always enough. Turn on the air conditioning if need be but keep an eye on the humidity levels.
If the grow room isn’t equipped with air conditioning, it might be worthwhile to purchase and install an air cooler. Just keep in mind that they work by pulling in air from outdoors and cooling it, so they don’t reduce humidity as an air conditioner would. It’s best to avoid using them when plants are in the flowering stage.
Hydroponic growers have another option. Instead of carefully regulating the air temperature, they can keep it within a reasonable range and lower the temperature of the water in their hydroponic setups using an aquarium water cooler. If the air temperature is in the 80s, growers can set their water coolers to somewhere in the 60s to keep their i49 plants happy and healthy without having to invest in air conditioning or air-cooling systems.
As noted above, relative humidity levels vary based on temperature. This makes regulating humidity a bit of a challenge, but it can be done.
Seedlings and clones do best in humid environments. They don’t have established root systems, so they pull in most of the water they need from the air. However, plants in the vegetative stage prefer lower humidity. They thrive when it’s kept within a range of between 45 and 55%.
Once they enter the flowering stage, your bruce banner strain plants become more prone to developing issues like bud rot. Growers can avoid this problem by keeping the humidity in their grow rooms to between 35 and 45%. Most experts also recommend lowering the humidity even more to around 30% right before harvest, when bud rot and mold are most common.
It’s rare for growers to have problems with low humidity. Plants produce water vapor as a byproduct of photosynthesis. They also introduce further water vapor into the air via evapotranspiration, a process designed to keep them cool. In the unlikely event that growers need to raise the humidity in their grow rooms during the seedling stage, for example, they can purchase humidifiers, mist the leaves of their purple haze weed directly, or just leave open buckets of water in the room.
Problems with high humidity are much more common, especially in the vegetative and flowering stages. Growers have a few options for dealing with it. It’s always best to start by ensuring proper ventilation, but if that doesn’t do the trick, it may also be necessary to install a dehumidifier.
Dehumidifiers work by condensing air moisture into water. Dehumidifiers also give off heat, so they can contribute to other indoor climate concerns. Growers can get around this by installing air vents to remove the hot air exhausted from the machines and direct it to outside the grow room.
When ventilating grow rooms, bear in mind that water vapor is not the only thing that will escape through the exhaust vent. Marijuana produces pungent odors, especially once it enters the flowering stage. For growers who value discretion, inline carbon filters are the way to go. They remove both odors and other air contaminants, ensuring that the air leaving the grow room is fresh and clean. Since essentially all varieties have some odor (i.e. both cbd seeds and thc seeds) there is really no getting away from this unless you properly filter your outgoing air.
Air quality is one aspect of indoor climate that is more difficult to control in indoor environments than outdoor gardens. Poor indoor air quality can reduce yields and increase plants’ chances of falling prey to powdery mildew and other airborne fungal infections. If the grow room isn’t properly ventilated, the air may also have low levels of carbon dioxide (CO2), which plants need to perform photosynthesis.
In a perfect scenario, cannabis plants would have access to plenty of CO2 brought in from outside, but they wouldn’t be exposed to things like mold spores, mildew, and fungi. All the plants would receive similar amounts of fresh air, and the air being replaced wouldn’t leave growers exposed.
The most common problems growers experience with poor air quality are bud rot and powdery mildew. Fungal infections are also more common in grow rooms with poor air quality.
Ensuring proper ventilation and installing a few fans can go a long way toward improving indoor air quality, but it isn’t always enough. Growers who want to avoid problems with mold and mildew should take the extra step of purifying air before it enters the grow room.
Carbon filters may be great for removing odors and some kinds of air contaminants, but they’re not the ideal solution for purifying the air coming into the room from outside. Air scrubbers do a much better job. They use pre-filters to catch large particulates, bag filters to remove mold, powdery mildew, and other smaller contaminants, and some even have HEPA filters to catch particulates as small as 0.3 microns in diameter.
Air purifiers are not great at removing odors, but that’s more of a problem when it comes to exhaust. As we’ve mentioned, in case you didn’t know some cannabis strains can get extremely pungent during flowering, especially some of the strong medical marijuana for sale in the USA. Growers who want to remove odors from the air entering their rooms from outside, for whatever reason, can install secondary carbon filters alongside their air purifiers.
Marijuana plants need a lot of light, but growers need to regulate light intensity and duration if they want to avoid damaging their plants. They should start by purchasing high-quality grow lights designed specifically for marijuana cultivation and following the manufacturers’ recommendations regarding distance maintained from the top of the plants.
In the seedling stage, plants from sativa seed or kush seed can benefit from round-the-clock light. Once they enter the vegetative stage, the plants need at least six hours of darkness to photosynthesize efficiently. Most experts recommend an 18/6 light to darkness schedule for this period. Growers can induce flowering by switching over to a 12/12 lighting schedule and should maintain this schedule until harvest.
Marijuana plants’ needs also vary according to their growth stage when it comes to light intensity. In the seedling stage, they need 5,000 to 7,000 lux. In the vegetative stage, they need 15,000 to 50,000 lux. In the flowering stage, they need 45,000 to 65,000 lux.
If the lights are too close to the plants, they will burn the leaves. If the lighting schedule is off, plants will experience photoperiod disruptions and may turn into hermaphrodites.
High-quality grow lights typically come with timers, which allow growers to switch their plants over from light to dark automatically. Some growers use the same lights throughout their plants’ life cycles, while others switch from MH lights to HPS lights when they change their plants over from veg to flower.
Climate control is one of the biggest advantages of growing marijuana indoors. Maintaining an optimal climate requires more than just turning the AC on in the heat of the day. It also requires paying close attention to humidity, lighting, and air quality. If they paid attention, growers should now have all the knowledge they need to make informed decisions about how to manage the climate in their indoor environments.