how hot is too hot

[maineharvest]

Is 90-95 degrees too hot for a grow room. I think my plants got a little burnt and stopped growing. They look alright now but its been a few days and they havent grown at all. Will too much heat stunt the growth and what is the perfect heat and humidity.

 

[Burnout]

72 to 75 anything over 95 and its dead. 72-75 are optimal temp.

 

[droboy420]

ya 90 or 95 is way to hot you need to put a fan and a exhast fan in your frow room

 

[LaserKittensGoPewPew]

Your plants can withstand those higher temps. Just don't push it over 90 if you can help it. As long as the root zone is kept down around 70-75 degrees it'll be fine and continue to grow.

 

[maineharvest]

I put a fan in the room and the temp is down to 80-84 degrees. Would the 90 degree temp stunt the growth of the plants for a while, because they havent grown at all for about five days now? The humidity is at 45%. Is that good?

 

[Mutt]

I have had a grow hit 90F @ 32%. It was tough but they made it. What also can help is if your running veg. stage then just switch to 18on/6off (max lights off) having the lights off during the hottest part of the day.
Like the others said ventilation is must. one fan blowing fresh in and old air out o'wise its an oven.
Happy growin.

 

[trichnut]

anything above 86 degrees will stunt growth.
here is an article from the College of Agriculture
and the web page. http://ag.arizona.edu/hydroponictomatoes/index.htm
Temperature

Both day and night temperatures influence plant vigor, leaf size, leaf expansion rate, and time to fruit development. Under low night temperatures, the rate of leaf growth is slower, and leaf size is reduced in young plants. Day and night temperatures should be carefully monitored. A general rule of thumb for most horticultural crops is for night temperatures to be approximately 5.5° C (10° F) lower than day temperatures. For tomatoes, day temperatures should be 21° -26° C (70° -79° F) and night temperatures around 16° -18.5° C (61° -65° F), although many new varieties do best with little difference between day and night temperature (check with your seed company for recommended growing temperatures). For seedlings, the temperatures should be constant, 20° -22° C (68° -72° F), then gradually acclimate the plants to the diurnal temperatures before transplanting.

High temps in excess of 30° C to 35° C will cause many different types of damage to the plants, such as inhibition of growth and even death. The physiological nature of heat damage is thought to involve a denaturation of some protein component of plant cells. Fruit abortion may occur at these temperatures as well. Temperatures lower than optimum will alter the plant metabolic systems to slow growth and again hinder fruit set.