Is heat really that bad for plants?

I started 5 nirvana big bud seeds near the beginning of June, and I'm just getting ready to harvest. I started them outside, and moved them to my attic, where temperatures were over 90 degrees for most of the summer. I planned to flower them all in two rubbermaid storage containers with a 400-watt light, but only one ended up being a female, so she got the whole thing.

I had the light on during the night to minimize the daily temperature spike, but I still had no cooling and temperatures got up to 105 degrees at the most. I had one 50 cfm bathroom fan for ventilation, and no CO2. My plant was attacked by both aphids and thrips before I finally got them under control about 5 weeks into flowering. Oh, and I topped my plant during flowering (2 or 3 weeks in), another no-no.

I ignored all the advice I got that my plant was doomed to a fiery death, following instead my own theories that my plant would do ok thanks to the massive amount of dirt (about 12 gallons) it had to grow in. Judge the results for yourself.

I harvested one cola already and got about a sixth of an ounce. That was 7 weeks into flowering. This weekend, it'll be 9. The cola i harvested wasn't even the biggest one, it was maybe fourth (out of 23), but it was getting burnt by the light so I cut it. The potency is just fine too. Like 5 people got stoned on about a gram and a half. Oh, and not a single hermie flower!

Anyway, I'm sure that if conditions in my attic were more ideal, I would have had a larger yield. But it was my only place to grow, and air conditioning was not feasible. Whatever I'll get is certainly better than nothing!

So here's my plant. I'm guessing about 3 ounces, based on past experience.

Khronik I had the same heat issues as you and one skunk69 turned hermie and the 2 NLxskunk were fine pulled 12 ounces wet had them in 18 gallons dirt each. I thought i seen a post from you in the local section that said your from the B-lo, if thats right then we both had the same heat issues being from the same area.:)

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Originally Posted by Cannab!s

You know man, you can lay those babies down in an L.S.T. and they'll put on a lot more weight. Are there trichs all over it? I had some Nirvana bigbud when i started, and it was sugar coated, huge. Not the most powerful punch but there was so much sugar on it, i was very, very pleased.

Hey if you look up apical dominance, you'll see the hormone family Auxins mentioned. Low Stress Training was pretty well figured out on O.G. and is a means of laying all the limbs over horizontally, to the point that as many nodes, on as many limbs, are on the same horizontal plane. It makes the plants go crazy in growth, because all those nodes kept at the same horizontal height don't have the brakes put on growth; the plants do very well.

Most people nowadays don't realize that Low Stress Training is more than random tying; and isn't untying once you start. That's called Partial Low Stress Training when that's done. A full L.S.T. is leveling the nodes on the limbs every 2 to 3 days: once any bud gets higher than the others, it ships Auxin below to the others, slowing their growth. The higher a few buds get, the more Auxin they ship below, slowing the others' growth and freeing up energy for themselves: but a proper L.S.T. that's done till the chop gives more weight than any training method. It takes about 15 to 30 minutes for a typical grow every 3 days or so.

I had bigbuds from that pack from Nirvana giving up more than an ounce of rock hard bud each off a little 250 back in the day; laying them over pays bigtime and those calyxes will fill in from end to end all along the limbs. Hope you enjoy growing out the rest of yours mine were pretty as a picture.

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I tried to do LST once and cracked a stem. I realize it's possible to do it without cracking any stems, but I'm still a bit wary. Anyway, I'm not disappointed with the results of topping. I nipped just the very tip off of the top bud, not the whole thing. All the side shoots immediately started growing a lot faster, and I ended up with 23 colas off the main stem, which ended up at a more or less similar height.

As far as trichromes, I have a lot, I guess. The leaves aren't as covered as I've seen in pictures of, say, white widow, but there's definitely trich coverage. I'll take a picture when I harvest, but this HPS light colors all my pictures orange, so you wouldn't see nearly as much detail under that.

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Originally Posted by socialistpete

Khronik I had the same heat issues as you and one skunk69 turned hermie and the 2 NLxskunk were fine pulled 12 ounces wet had them in 18 gallons dirt each. I thought i seen a post from you in the local section that said your from the B-lo, if thats right then we both had the same heat issues being from the same area.:)

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Yep, I'm sure it does depend on the breed. Right now I'm doing a grow of Mandala's Satori and Hashberry, since they're supposed to have great heat resistance. Of course, these'll be harvested November-December, so I'll have to worry more about cold than heat. Hope we don't have a repeat of last year's October weather! ;)

I gave away the rest of my Big Bud seeds, since right now I'm more interested in trying out Mandala's strains. Still, this was a fine strain, and everyone who's smoked it so far was surprised at how potent and long lasting the high is. Of course, they're all a bunch of noobs who mainly smoke street weed, but this is still a very well-performing plant.

The hotter you run, the higher yer humidity has to be- google "vapor pressure deficit"

rhizome: sort of, but a more accurate statement might be, "the hotter you run, the faster your plant will lose water." In that sense, it's true. During the hottest part of the summer I had to give that plant almost a gallon of water every other day.

Bud shot!!

Is heat really that bad for plants?

Is heat really bad for animals? If it's uncomfortable for you, it's uncomfortable to your plants. If it's so hot your productivity is diminished, it's the same for your plants. If it's so hot you get ill, then so will your plants. If it's so hot you die, then the plants will eat you so they can survive the heat.

100 - I've heard of it, don't recommend trying it.
95 - Perhaps ok, Likely not.
90 - Probably ok, but a little less would be better.
85 - Not optimum, but it'll do.

Nice looking bud!

Heat is bad for plants, but it does not mean you wont be able to yeld a large amount of bud from over-heated plants.

I think sometimes people forget that cannabis is just a plant. I have a plant that is outside that was exposed to 105 days, and 70 degree nights, low light (growing under another plant) and i stepped on it once when it was a seedling. It still grew, and its still flowering, no male flowers or anything.

they want to do their life thing, more then we want them to.

Buy a portable AC Unit , They are cheap and easy to move.
Also try to have Fans and also try getting the hot air out and cooler air from outside in.

Definetly plants will still grow in heat , but not optimum.

Good LUck

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Originally Posted by highallthetime

Definetly plants will still grow in heat , but not optimum.

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What he said. Way more problems to deal with. PH and nutes must be just perfect.

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Originally Posted by khronik

rhizome: sort of, but a more accurate statement might be, "the hotter you run, the faster your plant will lose water." In that sense, it's true. During the hottest part of the summer I had to give that plant almost a gallon of water every other day.

Bud shot!!

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Well, bud porn aside, a more accurate statement would be

In order to prevent stomatal closure at high temperatures, which will limit the availability of atmospheric carbon for fixation, a low VPD must be maintained.

Really, I don't make this stuff up. Here's a link.

he makes it up....:D

Khronik you order your seeds or go north to seed banks. Lately I've been going to Toronto and getting them in person. Are you going to vent with outside air this winter? I just put my next crop into flower today and with just the exhaust fan pulling air and leaving the intake fan off with the intake passage way still open I have maintained a temp of 84 all night so far under a 1000w HPS.

Opie - maybe. The way I see it, like Scrappie said, is that it's easy to keep your plants alive, and any optimizations after that will just improve your yield. I'm sure many of you have gotten better yields than 3 ounces from one plant under a 400-watt light, but i'm quite happy with that.

highallthetime - at the time I set this up, I wasn't working, and AC units aren't cheap. Also, the circuit that this whole system is on is a bit overloaded as it is. I already had to reset the circuit breaker once, and my lights weren't even on then! Also, since it's upstairs it's really hard to run another line up there from the basement. Still, my point with all this is that you DON'T need an AC unit in order to get decent results.

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Originally Posted by rhizome

Well, bud porn aside, a more accurate statement would be

In order to prevent stomatal closure at high temperatures, which will limit the availability of atmospheric carbon for fixation, a low VPD must be maintained.

Really, I don't make this stuff up. Here's a link.

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First, that's not talking about cannabis, which IIRC evolved in the mountains of India. At high altitudes, there would be a very large vapor pressure deficit. Second, it's not like the stomates just snap shut when the vapor pressure deficit gets too high. Your plant might grow a little slower, sure, but I never said the conditions I grew this plant under were ideal. Third, it's not particularly dry where I live, and the humidity in my grow room was usually 40-50%. Maybe if I lived in Arizona I'd have to worry about the air being too dry, but I don't.

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Originally Posted by socialistpete

Khronik you order your seeds or go north to seed banks. Lately I've been going to Toronto and getting them in person. Are you going to vent with outside air this winter? I just put my next crop into flower today and with just the exhaust fan pulling air and leaving the intake fan off with the intake passage way still open I have maintained a temp of 84 all night so far under a 1000w HPS.

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I considered getting my seeds in Toronto, but they're more expensive and still quite a ways from where I live. I just ordered them online from europe. I think it'll be more trouble than it's worth to grow in the winter, so I'll probably put my next crop into flowering pretty soon. I'll probably be ok flowering for a couple weeks in december, but I'm probably not up to having live plants in my attic in january and february. I think my attic is drafty enough that I don't need to worry too much about ventilation for the purposes of CO2 exchange though. ;)

However, I live in a house with four other people. The guy that owns the house is cool with me growing, in fact he smoked a bit too much of my crop already. His girlfriend was very anti-pot until she actually tried it, now she's fine with me growing too! :D One of the other guys we live with smokes a fair amount anyway, and he's cool. Another guy we told about it, and he's cool too. There's just one guy left who lives here that doesn't know about me growing. He'd probably be cool with it, we just haven't told him yet. Anyway, if he's cool, I may be able to build a new grow room in the basement. :D

Of course that would be kind of expensive, and the guy that owns the house isn't sure he wants a grow room as a permanent fixture in his house.

You can do a grow room in the basement pretty cheap. Winters long and cold and you def need a hobby:thumbsup:

I finally harvested today. It took forever. I had some unforeseen mold, but not much, and it doesn't smell. Now it seems like maybe a little less than my original estimate of three ounces, but it's still pretty damp, so I'll wait to weight it.

The jar in the back is leaves that had trichromes on them, and I couldn't bear to toss them. I'm not sure what I'll do with them yet. It's not enough for hash i think.

Don't toss those leaves unless you know for certain that you will not be running out of something to smoke in the not to distant future. You can get nice and toasty from smoking leaves with resin on them, you just have to smoke 2 to 4 times more than with buds. I see you have the leaves and buds in jars. I discovered that a vacuum sealer comes in real handy for a weed grower. It sucks all the air out of the jar (well, real close to all of it) and that greatly increases the life of the weed. Then you toss the jar in the freezer. Then one time about 6 years later when youâ??re desperate for a smoke, youâ??ll suddenly remember the jar that has by this time made itâ??s way to the very back of the freezer. Just make sure the weed is completely dry before freezing. The sealer also works great without jars, and theyâ??re pretty cheap now days.

Also the dried leaves are great for smoking resin in a regular bowl. Pinch some leaves together to get them ground up and put a pinch in a bowl. Put a little chunk of resin on top and ignite. If you do it right youâ??ll have the resin burned up before the ashes from the leaves get sucked down, thus stopping any remaining heated liquid resin from going into your pipe as well. It also helps make smoking resin a little less nasty. Unfortunately this is what I have resorted to at this time. Sniffâ?¦ Iâ??m drooling at the pictures you guys are posting. Nice work.

Be sure to try and get all that mold off your buds. Some people insist that it's really really bad to smoke, but then I've never seen any scientific proof. Just to be safe I wouldn't smoke it, even if it means you'll run out of weed.

I heard that mold is only bad to smoke if it's started to release spores, and if this is the case you can usually smell it. My stuff just smells like weed. And anyway, I heard it's only a major problem for people with asthma or certain allergies. I separated the stuff that had mold or might have mold on it out, that's what's in the box. The jar bud is clean. The moldy bud will probably end up with moochy friends anyway. :D

I weighed my bud today. It's not entirely dry, but it measured out to 3.5 ounces.

Oh, by the way, I like your signature Opie! :thumbsup:

Ok, I weighed all my bud today, and it came out to 3.08 ounces. If you factor in the 0.17 ounces I harvested already, that's 3.25 ounces total from this plant. Not bad for a plant growing in a hot, small, poorly ventilated attic. :D

So you guessed 3 oz earlier. I was going to say perhaps a little less, and now I'm glad I didn't. You can't guess much closer than that.

i had a problem with my leaves getting brittle and black tips ..temp 90

did you notice this problem?

now i have the temp 75-80 i have noticed am improvment, just hope it lasts

Brittle black tips indicates suffocation, increase your air flow drastically. The only reason you see an improvement at lower temps is the rate of transpiration is lower and the plant is not using up all of its available atmospheric CO2 before it has a chance to refresh. You are seeing the reason it is possible to run at higher temps if you use CO2.

i had to keep it shut at night because of the neighbours, but it simply got to hot 90d's

i've now sussed away to keep the doors open at night 75d's

i got a window open right next to them

plus i put a fan on them 3-4 hrs a day, or should the fan be 24hr????

No need to have the fan going 24 hours, in my opinion. 75 sounds great to me. Gotta keep em below 95.

I run fans 24 hours in my closet. It doesnt take long, even with the door open, for plants in the back corners to show signs of stress if I turn it off- and temps never climb above 80 in there. It's simply suffocation. In flower, I also run 24h fans but the bulk of the exhaust comes on at lights-on. Remember, it's not simply the heat you have to worry about, it's fresh air exchange, unless you run CO2.

Heats not "bad" for your plants, although it greatly slows your growth

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Originally Posted by azbudz

Heats not "bad" for your plants, although it greatly slows your growth

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im sure he hasn't figured that out in the 2 years he has had since the thread was started.