When to start flowering nutes? is it too late?

Imo just start gradually giving low levels of PK biased stuff along with your NK biased stuff, and gradually biasing more towards P rather than N.

I find it hard to judge on a photoperiod when outside. 2 year ago I had one that looked like it was in pre flower but the days where still getting longer. I started building up P and K and left my N where it was and started to get N deficiency. I ended up feeding them on the same ratios of NPK for ages until I was certain it was going to flower properly.

I've tried totally switching from flower to bloom nutes and I got signs of nitrogen deficiency. So, I switch to my flower fertilizer but also give supplemental nitrogen especially when she's growing like crazy during the stretch.

Hi Mate, they will begin to stretch quite a lot at the start of flower so you should keep feeding veg nutes. When the stretch is slowing introduce bloom nutes. Don't swap fully make a mixture of the two. Most people say 50/50 and then the next should be full bloom nutes. Hope this helps. Shes looking great btw 🙂