Help with heat stress?

Im heading into the 4th week of flowering…my guys are struggling i think with heat…problem i think is stemming from temp change in my garage (where tent is)…at night it gets cold now so i had to put a heater in the tent…the temp isnt getting especially hot but the plants seem to be struggling with it none the less…avg temp is low 70’s…autoflower gorilla glue…19 hours light on…theyve grown to about 4 ft…and are getting water now about every 3 days…leaves are canoeing and edge burning…trying to figure out how to stop the issue! Suggestions?

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How cold is the tent at night if you don’t run the heater? And maybe if you moved the heater outside (but near) the tent, might that help?

Minnesota…so it drops down to 30’s at night now (probs low 50’s in garage) i need to get a total garage heater but havent yet so the heater in the tent is necessary

Are you measuring the humidity in the tent? Could the issue be humidity caused by running rhe heater rather than heat from it? Just guessing here.


The heater actually gets the humidity down to the numbers i want…low 30’s…the heater is on a timing schedule, the humidity actually gets a little high when the heater goes off…low 40’s

If the temp is low 70’s your humidity should be around 44-34% for the ideal conditions.

Question, if you believe heat have you measured any temperature at the leafs or at the plant directly?

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My averages are probs right there in the middle

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That sounds OK, and is in the basic range @PiratedSoldier just referenced. Could the issue be unrelated to the addition of the heater? Is the heater affecting root temperature adversely?

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Then, if the temps at the plant match, I wouldn’t say heat or humidity.

Yes, this is where my thought is going.

VPD is a measurement at the plant not the room.

So if the plant is experiencing a different environment (too much airflow, direct heat, sitting over cold vent, etc). Your VPD and root environment is off.

Found it, here is a calculator you can use to get your actual VPD.


Could the heater being at ground level be affecting root temps?

Is there warm air actually blowing on them at root level? If so that may be the issue.

This is how I have my heater setup. Now this is a veg room so my tent is open, I am just needing the room to get to that temp.

If it is in the tent and facing towards the plants or roots I would change that.

For my flower tent, I use my heaters in the basement. I just keep that room at the temp I want, as the intake air will be that temp.

Yea technically the heat is blowing at pot base level…the overall temp (monitored at the stem) is low 70’s but technically that heat is blowing at ground/pot level

Can you direct the air into a corner of the tent away from the plants, and let the tent disperse the air?

I will shift things around and try and get that heat off the pot level

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Good luck. Not sure if it’ll help or not, but worth a shot!


My plants are also growing tall…4 ft now and problem seems to be worse at top…should i slow the upward growth…maybe theyre getting to close to light?

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Aside from a light breeze to strengthen the branches I wouldn’t want any direct heat or conditioned air blowing directly on the plants or roots.

Roots for larger plants do want to be a bit cooler. Seedlings like warmer soil as they are close to the top. But as they dig deeper they get cooler which is what they like, to a point.

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This is good information, how close are they to the light now?

Training? No, if she’s not happy this can hurt her.

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