Reddish Brown Leaves and Sugar Leaves? Cold maybe

[EastCoastGambit]

I have noticed some reddish brown fan leaves on my plants and the early buds sugar leaves had the same thing going on. I was thinking it was due to cold nigh time temps but could it be something else (deficiency) of sorts.

I'll post a photo in a minute.

 

[EastCoastGambit]

 

[EastCoastGambit]

 

[Creeperpark]

The best way to tell the difference between phosphorous temperature decline and phosphorous deficiency is to do a pour-thur, catch a little runoff, and test it. If the ppm has dropped low then raising the EC will keep the nutrients up enough till the end of flowering.

 

[Creeperpark]

Using an EC or TDS meter is a must for maintaining the perfect EC. Without one a person can only guess and hope for the best.

 

[EastCoastGambit]

Thanks. I'll keep an eye on the EC. Im typically not that technical and try to run my nutes fairly lean, perhaps this is folly.

 

[goingrey]

The purple is because of the cold. The yellow because of underfeeding. So both.

 

[EastCoastGambit]

Yes. If you are yellow after flipping to flower is there any good way to address it?

I need to add more N in veg.

 

[EastCoastGambit]

Ive already corrected the temperature swing issue.

 

[led05]

The best way to tell the difference between phosphorous temperature decline and phosphorous deficiency is to do a pour-thur, catch a little runoff, and test it. If the ppm has dropped low then raising the EC will keep the nutrients up enough till the end of flowering.

It’s a P deficit for sure, K & N too, Ca I’d bet as well & couple micros

OP, what is your daily temp ranges, I didn’t see it posted? Can you take pic of underside leafs & Petioles too?

The purple is because of the cold. The yellow because of underfeeding. So both.

Yes I agree but also believe purpling due lack P as well…

 

[led05]

Yes. If you are yellow after flipping to flower is there any good way to address it?

I need to add more N in veg.

I’ve got a garage room that can swing 40F in a day and I believe plants love it, though more often once really cold it’s more like 25F swings on average which I believe is nearly ideal to get the best quality from them….

The biggest threat with cooler nights is overly wet soil imo

 

[TanzanianMagic]

View attachment 18915880

It's November.

Molybdenum gets locked out with cold temperatures.

At a more advanced stage:

"Cold temperatures. Cannabis roots function their best at temperatures between 15 and 30°C, with some growers/researchers claiming the sweet spot is somewhere around 24°C. Below 15°C, the rate at which cannabis plants take up nutrients and water via their roots drops significantly, and at 13°C, cannabis roots undergo a mild shock. Nutrient deficiencies can occur when the root zone is exposed to cold temperatures over extended periods as plants struggle to take up nutrients from their medium/fertiliser."

Source

I can't see most of the grow. However if the pots are on the ground, it is useful to put them on a folded crate or some planks.

 

[EastCoastGambit]

I would say the purpling is more due to cold because it only affected a few leaves and not the whole plant.

My temps were probably 74 F lights on and 63F lights off for a minute.

My temps controller scrapped out on me and my household heat wasn't on yet. I replaced the controller and am now stable at 82 F.

 

[EastCoastGambit]

Pots are on the ground. Definitely have cold wet feet. I'll put some insulting down. Almost looked like bud rot, the color that is, thought I know it isn't. It affected one strain SD x S. Bubble and not the other, chem 91 x S. Bubble.

 

[led05]

I would say the purpling is more due to cold because it only affected a few leaves and not the whole plant.

My temps were probably 74 F lights on and 63F lights off for a minute.

My temps controller scrapped out on me and my household heat wasn't on yet. I replaced the controller and am now stable at 82 F.

63F is fine for low IMO, nearly ideal in fact, get days into the mid 80’s, bright ass lights & you’re golden brother

 

[led05]

Pots are on the ground. Definitely have cold wet feet. I'll put some insulting down. Almost looked like bud rot, the color that is, thought I know it isn't. It affected one strain SD x S. Bubble and not the other, chem 91 x S. Bubble.

Yeah, that’s definitely a big issue, I like to have my tubs up on casters for ease of movement but definitely also that reason too ^^ GL buddy

 

[EastCoastGambit]

Fuck me. Just opened the tent and now I have heat damage from the space heater.

 

[Hammerhead]

I agree, temp related. Cold causes all kinds of issues with Nutrient uptake. It also causes the medium to stay wet longer which causes the PH to drop. Plants need that wet/dry cycle in a soilless medium like Promix. ..

Be very careful with a space heater in a tent.. I would heat the room instead if possible.

 

[EastCoastGambit]

I agree, temp related. Cold causes all kinds of issues with Nutrient uptake. It also causes the medium to stay wet longer which causes the PH to drop. Plants need that wet/dry cycle in a soilless medium like Promix. ..

Be very careful with a space heater in a tent.. I would heat the room instead if possible.

I agree. I don't like it either. I try to do it safely via the thermostat in the heater and a secondary temp controller. Ideally I would have a room within a room thing where the heater would be outside the tent and I would be heating a small room. Keeping my basement at 75F isn't ideal. Maybe winter month grows are off the table for me for now. I have a family upstairs and am not looking to burn down my house. I have a nest smoke alarm right on top of my tent. I ran this setup last year without any issues.

 

[EastCoastGambit]

For now I'll just turn the temps lower and lift the pots off the floor. I thought the fans would distribute the heat better to avoid but it's also new and RH is down so plants were not pleased with me.