Plant temperature

No real difference between what a auto can grow or a photo. Temperature is linked to so many important metrics when it comes to growing cannabis, nearly every single environmental metric has temperature effecting it in some way or another. Bacteria multiplies 10x faster above 77f than below. Transpiration is the process of water flow from roots out to the stomata, this process is carried out during the day, the more gas exchange that happens the more suction force is used within the plant meaning more water is cycled. When the plant spits water out the stomata it is a endothermic process meaning it uses latent heat from the light to evaporate the moisture, in doing so it cools the surrounding air dramatically, the more transpiration that happens the cooler the leaf becomes. When transpiration is maxed out during daytime you need to apply -1F to -5F to the temperatures when calculating VPD for daylight hours. This is because vpd is more accurate based off leaf surface temperature than it is on ambient. Knowing this in order to max temp indoor ambient would normally be 77F (no co2) but if transpirationnis high then anywhere upto 82F ambient would give the leaf a temp of 77f or there abouts.With co2 above 1200ppm, you can go 86F or 92F if your feeling brave. Helps to remember the rate of water uptake also dictates rate of nutrient distribution, which will require more watering. A plant will transpire 3x as fast at 86f than 68f, with temp alone. Like everything else it's a balancing act, she can handle alot of extreme conditions the better question is how long can she handle it before its too much? Does the increase in transpiration mean the pots will be dry half way through the day? 🤔 The second she runs dry though you won't have long before the controlled 88F shoots up past 100F as endothermic cooling of leafs abruptly stops and damage begins. In my humble and often alternative opinion i find it beneficial creating enough stress to warrant disciplined growth while looking to utilize stress responses just enough for the response but being able to control and pull back from the brink before permanent damage is done, ride that line. 💪 same way you would push an athlete rather than a growing a couch potatoe who grows at their own leisure.

That’s a good question, it can depend on your setup and environment. If you’re talking about indoor growing, the sweet spot is usually around 28°C. Going higher can start to inhibit growth and flowering, especially if airflow or humidity isn’t ideal. If it’s outdoor, there’s not much you can do about the heat, but growers often use shade cloths or light covers to protect the plants during the hottest parts of the day. And yeah, you’re right: higher temps usually mean more frequent watering, but make sure the roots still get oxygen and don’t stay too soggy.

same as a photoperiod... will depend on genetics and other variables of your environment, too. No plant wil do well with 30c and 30%RH, for example. (or, very few will tolerate it). Howver, if the RH jives well and creates a proper resulting VPD it'll be fine. whether there's a benefit to going that high will depends on atmospheric co2. There is sgreater potential for photosynthesis at 30c, but it's just one of several factors to control in order to realize it.

I don’t think you should have the temp when growing above 85degrees anything above that will stunt growth

95ºF

if the spcae has more CO2, it can take much higher temps. I aim for 25-32c

It completely depends. Modern autos have genetics that trace back to most climates.. Past that, things like VPD and leaf temperature and active water content matter the most for ambient air temp. For solution/medium temp this varies widely with living soil being able to tolerate extremes in both directions, water being the most confining, etc.

Around 30°C is usually where it starts to get tricky for autos. They can handle short peaks if water and airflow are good, but I’d try to keep it a bit lower if possible. 26-28°C is a safer sweet spot for healthy growth — unless it’s outside of course, then you just gotta roll with what nature gives you.

Is it highest and tolerate? Or highest that does not inhibit = perfect temperature. So are you asking for a perfect or a maximum? If you are asking about maximum that is suitable for the plant. - Genetics. Next.. more watering. Of course this depends on many stuff, e.g. RH. Hope you got all the information you need. 👌👌👌👌👌