Growing in a colder temperature?

Thanks for the info., tyedye, you really seem to know what you are doing and i appreciate it!

 

LOL@stoniest weeds I just trying to grow weed i don't know about grow lights and all that jazz. I jsut keep my bud in the light, in a window. but im sure it's too cold becasue march sucks. (

 

I believe 50 watts p/sq.ft is recommended as "optimal", 30 w.p/sq.ft minimum. That in mind, a 400 is ideal for 8 sq.ft.(4ftX2ft) Personally, I feel circulation is one of the most overlooked, yet important aspects of ID growing. Without CO2 enhancemment, fresh air circulating abundantly is crucial.

here are some notes that I have stashed away on temps and affects. Don't recall the exact source, but a good read, never the less...

"Fine-tuning temperature and water for maximum quantity and quality.

Why waste light and electricity growing stem? Stretched-out plants are the bane of indoor growers. There are several ways to reduce internodal length and thus grow denser, more efficient buds.


tight internodes
Temperature control

The easiest and most under-used way to control internodal stretch is temperature control. Plant internodal length is directly related to the difference between day and night temperatures – the warmer your day cycle is as compared to your night cycle, the greater your internode length will be. The opposite also holds true; the closer your day and night temperatures, the shorter your internodes will be. Ever notice how as the warmer summer months approach, your plants begin to stretch? Part of this problem may lie in an overall hotter grow-room, but a larger factor is the increased difference between day and night temperatures.

Lets look at putting this to play in your grow room. Maximum temperatures should ideally never rise above 26°C, so you must do everything you can to prevent your room getting too hot (run lights at night, use exhaust fans, air conditioners, etc). An ideal temperature range is 24-25°C when the lights are on, and 22°C when the lights are off.

The temperature technique is most effective under a 12/12 light regime, which is ideal as this is when cannabis stretches the most. When the light cycle is brought to 12/12 we will raise the night temperature to the daytime level of 24-25°C. Space heaters on timers work well for this, and max/min type thermometers are ideal for
tracking temperatures.

It is during the first 2-3 weeks of the flower cycle that most strains begin to lengthen internodes, making it a very important time to control temperature, as this is when the framework for future colas is built. After this 2-3 week window we need to drop the night temperature back down to 22°C, as this is where the plant is happiest.


long internodes
As floral development begins we need to keep in mind that the total size of your buds is determined largely by average daily temperature, provided it does not exceed optimal. So if you are letting your day temperatures drop below 24°C or your night drop below 22°C, you are costing yourself in overall weight and harvest.

Once your buds have reached optimal size and and you have begun the flushing period, you may consider dropping temperature down to 17-19°C for the final week or two. This drop in temperature triggers anthocyanin production, which intensifies the colour of the floral clusters and makes for a showier bud, especially with "purple" varieties. This final temperature change is not always feasible and can be omitted.

For extreme height control you may even use warmer night temperature than day, but be very careful when running settings like this, as even a zero difference between night and day temperatures will lead to leaf chlorosis (yellowing) after 2-3 weeks.

Some things you will notice while using this technique are a change in the leaf angle, upwards during warm days and downwards during warm nights. There is also the chlorosis if this is done for too long. Neither of these symptoms is nutrient related and will fix themselves when the temperature is changed back.

 

hey grouchy. Lovely commentaries you post here for us to dwell in and apply to our local environment. What I have some trouble with is the temperature range used. given in deg F it goes from 71.5 to 79 The indoor thermostat for my dwelling is set to 80 (26.6) and afternoon outdoors temps are generally in the 87 to 90 range (31-33) and plants thrive! I am going to look at this node distance from the day/night temp differential aspect only and not assign much value to a ceiling such as 26 deg(78.8) and consider it absolute. b1

 

B1...

 

Well hmmm... it seems as if I am seeing a difference of opinions from the start of this thread. Which is better, colder or warmer growing temperatures? You say your plants THRIVE in 80F temps yet earlier posts say a cooler temp is preferred? I posted a new thread about the temperature range of cannabis plants and would really like to get to the bottom of this issue. What is optimal growing temps? Do different strains prefer different temperatures?

 

I run Co2 and maintain 78-82 day and night drops to 68-72.A max of 10 degree difference has never caused any negitive growth for me,but then different strains respond differently to different environments;hence the word pheno.Heat and low light levels are the proven stretch factors in my experience.I have seen amazing plants grown with a 20 degree day/night variable.50-60 watts per sqft flower and as low as 30 for veg.Remember,heat kills without supplimenting with co2.73-78 is what I recommend you strive for in days.

 

.....I agree with mean'.(73-78 is ideal) Temps below 60 F and above 80 F(no c02 supplimentation) have negative effects.