Did you have a nightmare in the grow room this summer? If so, then you are not alone. Summertime is great for outdoor weed plants but for the indoor weed grower it’s a different story with many cultivators having nightmares in the grow room, however there are solutions which can improve the situation.
So why are we writing this at the end of summer? Well, because it’s still fresh in the mind! If we published this post in March, when there is still frost on the ground, would you read it? Probably not. Cannabis cultivation is an ongoing learning experience, so pick up a couple of tips now and note them down for summer next year (it will come around soon enough…). If you’re growing cannabis in the southern hemisphere however, time to get preparing!
We caught up with some friends of Paradise with experience of growing plants in some extreme temperatures around the world to identify hot weather indoor grow room issues and discuss potential solutions. Here’s a summary of our discussion:
High Summer Grow Room Temperatures
Most weed growers will be aware that lights are generating extra heat in the grow room in the summer, but probably not so aware of just how much heat all those other electricity consuming components (fans, ballasts, drivers, pumps) are also contributing. In Australia and Southeast Asia, where temperatures hit the mid - high 30s (Celsius) - often pushing grow tent temperatures into the 40s –an air conditioning unit is the gold standard for making a more hospitable grow room environment. However, anything to increase the airflow (from fans to simply opening the door to provide at least some circulation of air) helps, as does moving non-essential electrical components (ie ballasts and drivers) outside the grow room. In humid regions a dehumidifier is also recommended for reducing the risk of mold according to @ptosis.stoner_sirek.
Best Lights for Summer Grow Rooms
For obvious reasons, in hot climates, LEDs are a natural choice for cannabis growers who are looking to reduce temperatures in their grow room, an area of specialist knowledge for Grow Lights Australia, who design full spectrum LEDs, built for efficiency. “In addition to offering a broader light spectrum (which can enhance growth, reduce flowering times and increase secondary metabolites such as terpenes, flavonoids and cannabinoids), LEDs convert more energy to photosynthetic light instead of heat (infrared). This means less power is required for the same area. LEDs also provide a more even spread over the canopy which avoids the issue of hot spots which can occur with HPS lights.” In southeast Asia LEDs are the choice for the majority of indoor growers.
Common Plant Problems in Summer Grow Rooms
Summer heat in the grow room will often lead to plants becoming stressed. Issues include increased propensity for plants to stretch and often longer flowering times for plants. A less well known issue is nutrient imbalances caused by higher levels of plant transpiration (leaf surface evaporation) leading to deficiencies in magnesium and potassium during the flowering period of cannabis plants. All that increased heat is particularly welcoming for pests and diseases too which can rapidly multiply in higher temperatures and begin to prey on plants whose immune systems have been weakened through heat stress. In southeast Asia the spider mite is a common pest problem.
Consider a Different Grow Medium in the Summer Grow Room
One growing option to counter the risk of hot weather issues is growing in a coco- coir medium (under LEDs). This is a soilless grow medium that can perhaps be described as a hybrid grow method between hydroponics and soil. It is becoming increasingly popular with weed growers due to the fact that it feels like growing in soil, with added advantages such as being not so hospitable for pests. Coco-coir also provides excellent water retention, while at the same time being hard to overwater.
Choose the Right Cannabis Seeds:
Is it time to plan your crops in accordance with the season? It makes sense to plant feminized cannabis seeds which have good heat resistance qualities in their genes. Some good options from the Paradise library include Wappa, Auto Wappa (both with excellent extreme temperature resistance qualities) L.A. Amnesia and Californian Gold (both grown by @ptosis.stoner_sirek).