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Yellowing Leaves and Possibly Black Necrotic Spots.


New Member
This is my Second Grow and I believe I may have more than one issue. My lower leaves are yellowing with black spots/marks. They sometimes turn light brown, crinkle up and fall off. Others I just put the littlest amount of pressure and they fall right off. As well it seems to be moving up the plant from the bottom. It seems to only be affecting my Northern Lights and not the Trainwreck sitting right next to it.

What Strain is it? One Northern Lights. One Trainwreck. Northern Lights is the one I'm having the issues with.
Is it Indica, Sativa or Hybrid? Indica. What percentages? Unknown
How Many Plants? 2 Total
Is it in Vegetative or Flowering Stage? Veg.
If in Vegetative Stage... How Long? 6 Weeks
If in Flowering Stage... How Long? No.

Indoor or Outdoor? Indoor
Soil or Hydro? Soil
If Hydro, Reservoir size? N/A
If Hydro, Reservoir Temperature? N/A
If Hydro, what type of Medium? N/A
If Hydro, what type of Setup? N/A
If Soil... What is in your Mix? Miracle Grow Potting Soil
If Soil... What Size Pot? 2 Gallon
Size (Wattage) of Light? How Many? 1 150 Watt HPS, 5 23 Watt 6500k CFLs
Is it Air Cooled? Reflector isn't air cooled but cabinet has passive intake and a 190 CFM Exhaust Fan With Carbon Filter.
Temperature of Room/Cabinet? Lights On-76-80F.
RH of Room/Cabinet? 40-55.
PH of Medium or Reservoir? Unknown, I'm waiting on my ph meter in the mail. I understand how important ph is my first grow went pretty well without one so I thought I could skip it. Stupid move.
Any Pests? Fungus Gnats. I've been letting the soil dry out pretty well between waterings. I also top dressed the soil with Mosquito Bits to kill the larvae. That didn't seem to help so I applied a layer of Perlite to the top of the soil, that seems to be helping more than anything else.
How Often are you Watering? Every 3-6 Days depending on how wet/dry the soil is.
Type and Strength of Fertilizers used? Initially I was using Miracle Grow All Purpose Plant Food. Initially at 1/4 Strength Every other Watering. Bumped up to 1/2 Strength Every other Watering. I'm going Organic so I've switched over to Alaska Fish Fertilizer 5-1-1 Full Strength every other watering.
Size or Square Footage of Room? Cabinet is 2 square feet.


Well-Known Member
I would get a bigger pot for her. Do you have roots coming out of the drainage holes in your pot?

Also, check the ph of your soil. Do note that it is normal for leaves to yellow and die off on the bottom here and there. That being said the upper leaves also look yellow at tips and down the edges so that would tell me lack of Nitrogen.

I do not have a ph meter my self for soil checking so I check the run off with a solution. You can find water ph solutions in any chain store pet department, measure the ph of the water going in and measure the run off.

The only things jumping out at me are ph, lack of nitrogen, and possible root bound.

Miracle grow is horrible horrible stuff for cannabis.

Merry Christmas!


New Member
Thanks for the response. I ended up leaching both plants and it made all the difference in the world. Initially I was thinking nitrogen deficiency but the problem worsened when I upped the nutrients. I had just transplanted both into there final 2 gallon pots and there are no roots coming out the bottom. I'd like to use a bigger container but my space is very limited. I have to agree on the miracle grow or really any soils with the time release fertilizers being junk for growing cannabis. Growing is the most peaceful and relaxing thing I've ever done. I find my self just watching them all the time during lights on of course.
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