Growing Cannabis During A Heatwave


I will try to give some tips on how to combat the heatwave without adding much or any extra equipment. So you have your grow in full swing and you realize that the summer temperatures are rising in your grow area a little too much. What if you can’t add an air conditioner to your grow space? What other options do you have beyond adding an a/c to the space?

Knowing these tips may just make the difference during the hottest parts of the summer and keep your plants happy and healthy.

Turn your lights on at night rather than during the day – Growing cannabis during a heatwave

One of the first things you can do, when you notice the temperature getting too high in your grow space, is to change the time the lights kick on. This may seem unnecessary, but I assure you it helps a lot! By switching your lights to kick on at night when the outside temp is cooler, you can help keep your tent temps in check.

As an example, my tent on a summer’s day can hit temperatures of 90 °F or higher without using my lights. This happens because the ambient temperature of the room outside the tent is higher than average. But when I switch on my lights in the evening and overnight my tent rarely reaches above the mid-80s. I recommend turning your lights on around 10pm to avoid the heat of the day. This simple adjustment can help tremendously.

Watering – Growing cannabis during a heatwave

Another thing to focus on is watering more frequently. Since higher temperatures leech moisture from plants faster than lower temperatures, plants will need more water than normal. It is important to check on your plants daily during this time so you can water them accordingly.

Frozen bottles/ice packs – Growing cannabis during a heatwave

Cool the ambient temperatures with frozen water bottles or ice packs. When the heat rises humidity can also rise and be difficult to control. It is important to cool your growing space without adding more humidity to the area, which can happen when you water more. A couple bottles of frozen water can be placed in front of your fan and throughout the tent to cool the area down over time. The best part about this technique is that you can reuse the bottles so you’re not wasting anything.

Exhaust – Growing cannabis during a heatwave

On hot days it is important to make sure that your exhaust blows air out of a window instead of back into the room where your tent is. If the exhaust is directed back into the room, you are just recycling the hot air. Blowing the hot air out a window is a great way to control temperatures.

Move your ballasts, if possible – Growing cannabis during a heatwave

Some lights, whether LED or HPS, have removable ballasts. You can mount these outsides of the tent to lower the internal temperature. If by chance ballast cannot be removed, then add a fan to blow across the top of the ballast; this will help cool it down.

Add more fans – Growing cannabis during a heatwave

If possible, you can add more fans to your grow area. If you are out of space in your tent you can open the tent door and blow air in from outside of the tent. If you have a part of the house that is cooler than where your tent is, you can use fans to blow cool air from that area into the growing area. You can also use window fans to blow the hot air out of the house by facing the fans outside.

During the night when it’s a bit cooler, open as many windows as possible and position a fan to blow in and another fan to blow air out, this will help create a cross breeze and help cool off your space. Be sure to close all the windows and stop the outside air from blowing in by 11am or noon, this way the rising temperature doesn’t make your home too hot.

Blackout curtains – Growing cannabis during a heatwave

The darker you can keep the room, the cooler it will remain. Opening windows and curtains at night and using blackout curtains during the day can help reflect the heat.

Move the tent to a cooler part of the house – Growing cannabis during a heatwave

This is one of the more extensive methods as it requires everything to be moved. By relocating the tent to a north-facing room you can help keep the temperature slightly cooler.

By doing one or more of these tips, you just might be able to keep your plants cool enough to keep them happy and growing throughout these hot summers. The point of all this is to lower the temperature as much as possible at night so you get a jump start on the hot temperatures during the day. Most importantly: just stay vigilant so that you can do what you need to in order to keep your conditions just right. We hope this helps keep you prepared for the heat of the summer!

As always if you have any questions you can message our Instagram or Facebook and we’ll be glad to help you out! We’re happy you’re on this journey and we want to help in any way we can.

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