Hello all – this is my second grow. First time outdoors. I germinated seeds on May 9th (I have 4 plants, two Skittlz, one Girl Scout Cookie, and one The Bomb). The grow has been going very well up until this last week. I noticed the lower leafs on one plant was developing brown spots and is now starting to curl. This is now happening on 3 of the 4 plants (all but The Bomb).
I am in the PNW and it has been VERY hot the past several days so initially I thought it could potentially be not enough water so I have kept a closer eye on that, but I think it is more likely to be either (A) Nutrient Burn (B) Phosphorous Deficiency or (C) Potassium Deficiency.
When watering I currently utilize Root Farm Base Part I and Veggie Part II and balance the PH level.
I have attached some pictures - it would be great to get any advice on what may be going wrong and how to rectify it. Obviously, the action take for option (A) is drastically different than (B) and (C).