More on the basics of growing marijuana
Welcome back Dudes and Dudettes! Looking back, we covered our first basic necessity of plants in the last edition.
A quick review of the nine key factors: light, temperature, humidity, wind, CO2, root zone temp, water, nutrients, and oxygen.
Let’s continue with the discussion on the basics.
Temperature, who doesn’t love the right temp?
Walking out on that summer day when the light is just right, and breeze is comfy. People enjoy those days and so do the plants. When we grow indoors, we have to create the ideal environment that the plants want.
Since plants experience this reality differently than we do (do plants have 5 senses???). The space needs to be created with their senses in mind. We do know that plants use colors of light differently than our eyes, so it stands to reason that temperature means something more to a plant than should I wear a jacket today?
When we are talking temperature, we are primarily talking air temperature. What effect can air temperature have on plant’s ability? Well, just like you, plants don’t like to be too cold or too hot.
When the plants get too cold, so cold, they could freeze. That’s bad news and plants generally don’t recover, same thing when they get too hot, they burn. Temperature and Humidity are in the driver’s seat when it comes to plant performance. It won’t matter if you have the right lights, soil, food… if the temperature and humidity aren’t dialed in to the Sweet Spot.
Going forward when we talk about the Sweet Spot for air temps, we are referring to the range of 75-82 Deg F. The Sweet Spot will extend further into the other environmental factors but today we are talking temperature. When the air temps are in that range, we know based upon experience the space is ideal for the plants.
Temperature plays a role in the plants ability to tell seasons, along with night length and other environmental factors.
We want to mimic nature indoors as much as possible.
That means the garden will need an air conditioner or enough outside air flow to keep the temps in the Sweet Spot!
Transpiration, the plants ability to move water from its roots to it shoots is primarily dictated by temperature. Leaf temperature to be exact. Air temperature obviously correlates to leaf temperature. So, for how air temp relates to leaf temperature, there is no direct conversion.
Basically, to test leaf temps, an infrared thermometer is needed to read the temperature. That being said, we can estimate the leaf temperature is close to air temps.
Science has shown us that 76 deg F is ideal leaf temperature. Ideal means, the plant is kicking at 100% transpiration. Every degree above 76 is supposedly 10% less transpiration. So by increasing leaf temps by 5 degrees, can limit the plant by 50%!
Temperature is important.
All that being said and we have not touched on the difference between day and night. To this point, we have been talking daylight hours. When it comes to night time does temp matter? The plants are not transpiring…
Well, yes night temperatures matter very much. Again, when we think about mimicking nature, in the late spring through summer, the night temps stay relatively high. Noticing that the day and night temperatures are fairly close, we can assume we want a warm night during veg and during the first few weeks of flowering.
As you take control of these environmental factors and attempt to copy Mama Gia in your basement, you notice that as fall creeps in, we get warm days and cooler nights. Then as we watch the plants during that time of the year, we see the trichomes start to take shape. Ah, HA! That’s right, you got it!!!
Pro-Tip: Keep the day and night temps close during veg and early flower but colder nights during the end of flower to really drive the essential oil production along with the fragrance of the plants.
What is even more fun, if you have the ability to really control the plant’s environment is have a 20 deg F or greater temperature swing in the air temperature. The plant will start to purple!
It’s all a big experiment but we have seen proven path’s for success!