Toxicity or deficiencies? Help!

Hello, im hoping someone can help shed a little light on what i am dealing with. I am growimg 1 northern light and one blue cheese outdoors. I am probably a month or so into flower. The last couple weeks i keep getting leaves that are yellowing and then turning brown. They don’t seem to start typically just at the ends but rather in the middle of the leaf area. Started with just a few here and there but now its at least a few leaves a day being effected. Definitely getting conciderably worse by the day. The lates development as of today are leaves completely curling up. Im thinking mobile deficiency as it started with older bigger fan leaves and now is showing up in newer growth. I thought at first potassium deficiency so i added in bone meal a few weeks back. I was told nitrogen toxicity so i cut back on tiger bloom. But my leaves are also not dark dark green like nitrogen toxicity would cause? Now im thinking maybe phosphorus? My ppms are only about 600 as of last week. But i added a few gallons of water today with sledge hammer. Maybe give a reset. Any input on what im missing here would be much appreciated. Thanks in advance!


Perfectly normal for a flowering plant. You could remove a bunch of older fan leaves which will open the plant up to more air and light. This is an especially good idea if you live in a humid climate.

I would also suggest you get on a pest control program (if you haven’t already). I recommend using two products: Captain Jack’s Dead Bug (CJDB) and Safer Caterpillar Killer. These rely on different bacterial strains lethal to a variety of garden pests and leaves no toxic residues. I would also plan on doing a bud wash at harvest.

Plants look fine.


Ok good! Stressing me out! I do a preventative weekly pray with blue magic. I had a short bout with powedery mildew. After a few milk and water treatments i think im ontop of it now. Luckily i live in a dry climate. Just had to get through our seasonal monsoons. I was so happy just having such beauty lush plants all summer i definitely dropped the ball on defoliating. But i have been removing a handful of leaves everyday due to this yellowing issue. Hopefully not enough to stress the plant at this stage. Thank you for assistance!

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That’s what they pay us the big bucks for LMAO.

If they were my plants I’d remove everything in the bottom 1/4 to 1/3 of the plant and any older fan leaves on the rest. That will divert more energy into flower production near the tops of the plants.

WPM is a pain and if you had it you still do. I did the whole milk thing and baking soda is another, but the best is a mild solution of peroxide and distilled water IMO. 1/4 cup in a quart of distilled (important if storing) sprayed on the plant thoroughly. I’d do this within an hour of twilight to avoid burning and expect to get a bit of scruffy looking leaves due to the peroxide drying it out. Peroxide is great as it leaves no residue at all. Unlike the scale from milk proteins which I would not recommend on a flowering plant anyway.


I have heard powdery mildew is pretty much impossible to eradicate once established. Hard for me to tell for sure since as you mentioned the milk has left a residue. Not to mention the whole area smelled like milk. Not in a good sense lol. But i have definitely been able to keep the mildew at bay at least it seems like. I will try the peroxide if it becomes a problem again

As far into flower as i am do you think it would be safe to take that many leaves at this point? Ive been pretty hesitant this far along.

And Yes! Definitely planning a bud wash.

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Dont take more then 1/3 of the total foilage at any one time. Also, defoliate and feed on the same day. Haircuts can be stressful and having nutes readily available will reduce that stress.


Perfect! Sounds good! Thanks for the info!

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We are out of town and my middle child is plant sitting. She was concerned about the yellow leaves also thinking she killed my plants with one watering!

I told her it is normal this time of year. I have been pulling the yellow inside and bottom leaves for a while.

Your girls look very nice

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Thank you!