When do trichomes form?

My fastbuds Gorilla cookies auto's seem like they were stuck in preflower for 3 and 1/2 weeks. Seems like they're just now breaking out of it. Getting a lot of bushy white hairs coming from top of the plant and all the tops from the side branches. Seems like with a few other plants I've grown as soon as the white pistols start to pop out either almost immediately or soon afterwards I start to see trichomes. This doesn't seem like it's doing much. Any thoughts? Pics attached20220810_131551.jpg20220810_155755.jpg
 
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