How hot is too hot for direct sunlight?

It's really heatin' up in the central valley this time of year, and I am curious as to how hot is too hot for outdoor temps in direct light? I know landrace has a lot to do with it, but it's going to be in the high 90's this weekend, and possibly dipping into the 100's by early next week. When is a shade cover needed?

Now! The stomata on the underside of the leaves will shut down around 90 deg.

Im curious about this too?? there have been times where it truely seemed like my plants halt growing in high temps, is covering with shade netting sacrificing too much light or is it simply bringing the temps down?

When it is too hot the plant shuts down to keep from losing too much water through transpiration. It will also droop it's leaves to reduce it's profile to the sun. It will continue to grow in reduced light if the temp is within it's happy range. It will not continue to grow if it is too hot.

thanks jessy i guess I will stop being a pussy about sunlight and throw some shade netting up on the extreme temp days

Man it's over a 100 here I'm on the east coast and my plants are absolutly loving every second of it as long as I water em ever other day

It's been in the mid 90's here and my plants also love it. But some I have to water everyday. They're definitely growing. I think the key is enough water.

Lookwhatimblazn said:

Man it's over a 100 here I'm on the east coast and my plants are absolutly loving every second of it as long as I water em ever other day

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You probably have some humidity there. Around inland California low humidity, below 40%, is the norm. That is really hard on plants when the temp is up too.

funny all my plants get direct sun and its gonna be 99 or so for the next ten days... and I feel like everything growing like fucking crazy.

jessy koons said:

You probably have some humidity there. Around inland California low humidity, below 40%, is the norm. That is really hard on plants when the temp is up too.

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exactly.........

So instead of using shade netting maybe I could just add some humidity once or twice a day by misting or spraying down my plants with plain water during the hottest parts of the day? I guess its not adding humidity in the long run but its keeping the plants cool so they wont go into water saving mode and stop growing...just some thoughts

Sativa will handle it ,indica will go into lockdown and wait for the 'rains'. Make sure the hole /pot is well prepared watered and mulched also use water crystals. For now just water every day.

It depends a lot on the strain, also. Mandala seeds supposedly can flower in 120 degrees. My Mandalas, Rishi Kush and Krystallica, have shown no stress at 108 so far and grew about 1 1/2" a day during that temp.

Soil temps are important also. For instance, if it's 115 and your plants are hardy, with a soil temp of 85, they should breeze. If you're in pots shade them, paint them white, mulch, etc. I just measured my ten gallon Rishi, which is very well shaded, kept moist, and mulched and the soil surface temp is 82. My planter plants are in a very hot area and the hottest soil surface temp is 91. When the perlite is moved the roots are visible on the soil surface, They have 2-4" of large perlite as a mulch. A soil area next to the planter is measuring 142. It's only about 100 degrees in the shade right now but that gives you some numbers. Do a surface watering once or twice during the afternoon. Called syringing, it's very helpful.

I have yet to use my top shade cloth but will at around 110 just to be safe.

That is an option but if the air is very dry any misting will dry up within minutes. Keeping the soil area around the plants wet will help to keep the local area humid.

Like I said I'm watering every other day at night and just dumping te water right ontop of em and they couldn't be happier they love this hot weather and I'm near the bay so it's prob real humid it's just so dn hot out I can't even go ole a ciggerette without feeling like gonna pass out lol

Hot summer in the midwest . My Con Cheese (RP) are doing well in it. I water not so much though.

Yeah I got 5 in 5 gallon buckets that r orange and I give em 1 bottle of water each (just wat I use to measure) and I could prob get away with every 3 it just sucks hiking thrpugh my back feild in this heat lol

Haha it's getting dark out and looks like a storm guess I'm gonna make my self a dark an stormy and hope that it does lol

They'll be fine as long as you don't let the soil or pots dry out. Mulch mulch mulch

Good to know guys, it has been scorchin' lately! Picked up a nice shade cloth to cover my ladies up, and make em nice and comfy I got a Mr. Nice (indica dominant) and a White widow going.