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cannabis leaves droop at night

Plants Start Drooping Toward Night Time

ArmedGeek

I’m running 18/6 veg light. Three weeks in veg (about the time they started stinking) i have noticed three hours prior to night, the plants start drooping. When this occurs, they look extremely pitiful and sad, very sad.

It just started happening the last couple days and temps/rh have been the same since week 1 of veg. However when the plants wake up, they look extremely healthy and perk right up.

There are many threads regarding this topic, but i have yet to find the exact reason why. My natural thoughts are this is normal, as the plants have learned the light cycle. Around three hours prior to drooping, they are exhausted from the days light, and are literally getting ready for night time.

I could use some expert opinions on this topic. I have thought about changing my light cycle to 16/8.

DWC
RH 46-58%
PH 5.8 (rarely any swings but adjusted within hours)
600w LED 28″ away from canopy
Temps 73 f night 76-78 f day
Fans running over canopy.

Smerb

I’m running 18/6 veg light. Three weeks in veg (about the time they started stinking) i have noticed three hours prior to night, the plants start drooping. When this occurs, they look extremely pitiful and sad, very sad.

It just started happening the last couple days and temps/rh have been the same since week 1 of veg. However when the plants wake up, they look extremely healthy and perk right up.

There are many threads regarding this topic, but i have yet to find the exact reason why. My natural thoughts are this is normal, as the plants have learned the light cycle. Around three hours prior to drooping, they are exhausted from the days light, and are literally getting ready for night time.

I could use some expert opinions on this topic. I have thought about changing my light cycle to 16/8.

DWC
RH 46-58%
PH 5.8 (rarely any swings but adjusted within hours)
600w LED 28″ away from canopy
Temps 73 f night 76-78 f day
Fans running over canopy.

ArmedGeek

The girls tend to be drooping and sad looking a couple hours prior to night. During night, i can’t see what they are doing but when lights come back on, their healthy looking and have perked up. I don’t believe night is the issue. I can’t seem to figure out what’s going on those few hours right before they go to sleep while the light is still on.

To answer your questions, i don’t have the fan circulating at this time and its pointed side ways toward my tent. However, it’s a 16″ hurricane and is too strong to start circulating. On low, the leaves/plants still experience subtle air movement and sway but the air is gently but constantly hitting them at all times. The leaves are slightly moist to the touch and a little cold.

Smerb

The girls tend to be drooping and sad looking a couple hours prior to night. During night, i can’t see what they are doing but when lights come back on, their healthy looking and have perked up. I don’t believe night is the issue. I can’t seem to figure out what’s going on those few hours right before they go to sleep while the light is still on.

To answer your questions, i don’t have the fan circulating at this time and its pointed side ways toward my tent. However, it’s a 16″ hurricane and is too strong to start circulating. On low, the leaves/plants still experience subtle air movement and sway but the air is gently but constantly hitting them at all times. The leaves are slightly moist to the touch and a little cold.

ArmedGeek

Veg thrives between 50-70 rh. However, it is totally dependant on the type of strain being grown. Some indica prefer dryer climate in comparison to other sativa strains simply because of the environment their originally from. I see what your saying, but I wouldn’t consider leaves being kind of cool to the touch to cold with 78f temps. This is actually much higher than I like. Also, being that I’m in bubblers I’m not root bound.

I do however agree that over watering/root bound would contribute to droopy leaves in a Coco/soil grow medium. With that said, I would expect droopy leaves the whole time if over watered until dried out, or until transplanting due to root bound. My rh and temps are within range, I don’t top feed and I’m dwc.

This has to be part of a plants life cycle in terms of the growth cycle. I’m just trying to understand what’s actually happening in technical terms for a complete understanding to broaden my knowledge.

Smerb

Veg thrives between 50-70 rh. However, it is totally dependant on the type of strain being grown. Some indica prefer dryer climate in comparison to other sativa strains simply because of the environment their originally from. I see what your saying, but I wouldn’t consider leaves being kind of cool to the touch to cold with 78f temps. This is actually much higher than I like. Also, being that I’m in bubblers I’m not root bound.

I do however agree that over watering/root bound would contribute to droopy leaves in a Coco/soil grow medium. With that said, I would expect droopy leaves the whole time if over watered until dried out, or until transplanting due to root bound. My rh and temps are within range, I don’t top feed and I’m dwc, so no root bound.

This has to be part of a plants life cycle in terms of the growth cycle. I’m just trying to understand what’s actually happening in technical terms for a complete understanding to broaden my knowledge.

Smerb
ArmedGeek
ArmedGeek

I found the below information in a different forum. I asked for technical, but this might be too technical =]

Leaves:
The exchange of oxygen and carbon dioxide in the leaf (as well as the loss of water vapor in transpiration) occurs through pores called stomata (singular = stoma).

Normally stomata open when the light strikes the leaf in the morning and close during the night. The immediate case is a change in the turgor of the guard cells. The inner wall of each guard cell is thick and elastic. When turgor develops within the two guard cells flanking each stoma, the thin outer walls bulge out and force the inner walls into a crescent shape. This opens the stoma. When the guard cells lose turgor, the elastic inner walls regain their original shape and the stoma closes.

Time Osmotic Pressure, lb/in2
7 am 212
11 am 456
5 pm 272
12 midnight 191

The table shows the osmotic pressure measured at different times of the day in typical guard cells. The osmotic pressure within the other cells of the lower epidermis remained constant at 150 lb/in2. When the osmotic pressure of the guard cells became greater than that of the surrounding cells, the stomata opened. in the evening, when the osmotic pressure of the guard cells dropped to nearly that of the surrounding cells, the stomata closed.

ArmedGeek
dannyk892009
dannyk892009
ArmedGeek
CaliRooted
PharmHand

Mine do it in veg sometimes too. There’s something called the daily light integral, it has to do with the amount of light intensity and duration a plant receives in a 24 period. It’s usually recommended ( by lighting companies like gavita)that you veg with less intensity than flowering because the plant is typically receiving 50% or more hours of light per day 18vs 12. This is because a plant can only process so much intense light in a day. In nature a plant would NEVER receive 18 hours of intense light in a day.

When your plants droop like that the stomata are mostly closed which means it’s not photosynthesizing efficiently maybe even photorespiring which actually wastes energy. I would bet if you or @CaliRooted were to dim your lights or reduce intensity for the entire 18 hour period your plants would stay perky for the whole lights on period.

Guys like jungle boys have realized this so to save electricity they’ll veg for 12 hours intense light and 6 not so intense. I used to work at a coop where the rooms were on 12 hour flip flops, when our veg room was full we’d veg in the flower rooms 12 hours intense 6 hours overhead fluorescents and the plants grew just as fast as the veg room plants. You’ll hear guys say that you can veg under 24 light and you can but try doing it with intense light and you’ll end up w some sick looking droopy plants. I’m a geek too bro:eyepiece:

nicefellow

Mine do it in veg sometimes too. There’s something called the daily light integral, it has to do with the amount of light intensity and duration a plant receives in a 24 period. It’s usually recommended ( by lighting companies like gavita)that you veg with less intensity than flowering because the plant is typically receiving 50% or more hours of light per day 18vs 12. This is because a plant can only process so much intense light in a day. In nature a plant would NEVER receive 18 hours of intense light in a day.

When your plants droop like that the stomata are mostly closed which means it’s not photosynthesizing efficiently maybe even photorespiring which actually wastes energy. I would bet if you or @CaliRooted were to dim your lights or reduce intensity for the entire 18 hour period your plants would stay perky for the whole lights on period.

Guys like jungle boys have realized this so to save electricity they’ll veg for 12 hours intense light and 6 not so intense. I used to work at a coop where the rooms were on 12 hour flip flops, when our veg room was full we’d veg in the flower rooms 12 hours intense 6 hours overhead fluorescents and the plants grew just as fast as the veg room plants. You’ll hear guys say that you can veg under 24 light and you can but try doing it with intense light and you’ll end up w some sick looking droopy plants. I’m a geek too bro:eyepiece:

nicefellow

Mine do it in veg sometimes too. There’s something called the daily light integral, it has to do with the amount of light intensity and duration a plant receives in a 24 period. It’s usually recommended ( by lighting companies like gavita)that you veg with less intensity than flowering because the plant is typically receiving 50% or more hours of light per day 18vs 12. This is because a plant can only process so much intense light in a day. In nature a plant would NEVER receive 18 hours of intense light in a day.

When your plants droop like that the stomata are mostly closed which means it’s not photosynthesizing efficiently maybe even photorespiring which actually wastes energy. I would bet if you or @CaliRooted were to dim your lights or reduce intensity for the entire 18 hour period your plants would stay perky for the whole lights on period.

Guys like jungle boys have realized this so to save electricity they’ll veg for 12 hours intense light and 6 not so intense. I used to work at a coop where the rooms were on 12 hour flip flops, when our veg room was full we’d veg in the flower rooms 12 hours intense 6 hours overhead fluorescents and the plants grew just as fast as the veg room plants. You’ll hear guys say that you can veg under 24 light and you can but try doing it with intense light and you’ll end up w some sick looking droopy plants. I’m a geek too bro:eyepiece:

I'm running 18/6 veg light. Three weeks in veg (about the time they started stinking) i have noticed three hours prior to night, the plants start drooping… ]]>