First outdoor grow, and not sure if this is normal looking for what I guess is week 4? The lowest leaves on lower leaves are starting to yellow like you can see in the picture. It's not all of them. The leaves closest to the top / the colas themselves are mostly green, but wasn't sure if there was a nutrient deficiency or if it's just starting to drop its fan leaves? I noticed very small brown tips on some (wasn't until a heat wave so not sure if that affected it...). Growing zone 9 (8k feet elevation Colorado mountains).

I'm doing an organic no till grow with red wigglers in the soil, uncle Jim's worm food, and supplementing with a banana / avocado every few weeks. They've looked perfect / green up until about this week so wasn't sure if it was just normal flowering to start yellowing the fan leaves / dropping them this early. Any feedback is appreciated. Thanks