As BG said the exo is a great example of foxtailing through genetics no matter what temps light etc she will foxtail. Then i have had a og foxtail from top to bottom just from overfeeding, i actually took cuts of it and grew out many times and it never foxtailed again although being subjected to many different types environment with just less feed.
If the foxtailing is just at the tops imo its the plant making its last ditch for life and of course genetics will play a big part of this.
But tbh if it smokes well who gives a ....
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