5th week flowering Yellowed/Curling leaves

I've got several plants in the 5th week of flowering in a Sunhut grow tent with 600w HPS Cool Tube that is cooled by a 6" Max Fan hooked up to the Cool Tube duct. I also have another 6" Max Fan ventilating the tent as well as two Holmes 31" oscillating tower fans to keep air circulating.

There are two strains growing Afghani Kush and Blueberry Mystic. Been using Fox Farms soils and their line of nutrients. So far the plant growth has been very good, but in the last 10 days I've noticed some of the fan leaves on the Blueberry Mystic as well as the Afghani Kush started to turn yellow and wither. These leaves are at the top and mid levels on the plant.

I've read that some of this yellowing and curling is normal, especially with Indicas in the last weeks of flowering, some posts recommend flushing, others don't, I don't know whether this could be nutrient deficiency or excess.

I've taken a few photos, and if anyone could identify what is causing the leaves yellowing and curling as well as a remedy, I'd certainly appreciate it.

Thanks,

Rob

just signs of nitrogen getting sucked into the buds to make leaf matter, happens to all plants in the winter when they make seeds and drop their leaves. keep pumping flower nutrients into those buds and i bet theyll get 3x as fat in the next 3 or 4 weeks. that blueberry mystics looking nice, it gets its true color in the end though.

Looks like nute burn.

Thanks for the responses, I appreciate all the input. I'm sort of inclined to believe that it's a normal part of the flowering cycle especially with Indicas. per other threads I've read, and I've always been light with the nutrient doses specifically to avoid burn, as I've experienced that before. However ... if it's indeed nutrient burn, will flushing help correct it? If I do flush what would be the recommended nutrients to get back into the feeding cycles. I've been using the Fox Farm line of nutrients.

Crazeyhazey..... yeah, it looks like they've finally started to bulk up in the last few weeks. Those Blueberry Mystics were very hardy plants throughout the clone/veg and now flowering cycle. They look identical in their physical appearance; I'm hoping that it has strong pain medicating properties as I've got several diagnosed illnesses that are very painful at times, that's led to my interest in Indicas although I'd like to try some strains of Sativas that would help with serious Arthritis in back and knees. Thanks again, Rob

I've been reading some of the sticky threads here about Plant Problems, could the yellowing pattern on the leaves in the pics above be Magnesium deficiency?
Appreciate any help as I don't want to screw this up so close to the harvest. Thanks, Rob

maybe its a burn so you might wanna flush if the deficiency is spreading fast, but if its getting dryer in wont hurt to wait another day. drop a pinch of epsom salt in your next water and maybe try to get some rainwater, it always helps my plants get their nutrient levels back to normal and flushing them with it helps them suck up some vital organic minerals, not to mention its gonna be really aerated since it fell from the sky.

keep posting pictures, it helps when you know what could being doing better. and if youve got some pains i really suggest some heavy sativas(ak or some sour diesel which is more of a hybrid in some cases) and heavy indicas(maybe some afghani or some aurora, im growing it now and its super vigorous), mixing them in edibles makes a great lasting high but i like vaporizers.

crazyhazey said:

maybe its a burn so you might wanna flush if the deficiency is spreading fast, but if its getting dryer in wont hurt to wait another day. drop a pinch of epsom salt in your next water and maybe try to get some rainwater, it always helps my plants get their nutrient levels back to normal and flushing them with it helps them suck up some vital organic minerals, not to mention its gonna be really aerated since it fell from the sky.

keep posting pictures, it helps when you know what could being doing better. and if youve got some pains i really suggest some heavy sativas(ak or some sour diesel which is more of a hybrid in some cases) and heavy indicas(maybe some afghani or some aurora, im growing it now and its super vigorous), mixing them in edibles makes a great lasting high but i like vaporizers.

Click to expand...

Thanks for the response crazyhazey, I'm going to see about flushing as you suggest but I want to get some decent water. Rainwater is rare here, I'm in North Scottsdale, AZ and we haven't had any decent rain here for about 4 months. we've been in a drought for over 15 years,

The yellowing/drying condition hasn't got any worse but I'm still trying to identify the cause and correct it. The buds look healthy and have continued to grow and fatten.

Thanks again, Rob