A friend of mine has some indica dominant plants in his greenhouse, he is in the southwest, and his plants have still not flowered, they are in 25l pots with blood and bone meal and regularly being topped up with proper nutrients. This friend o mine wants to know if changing the nutrients to flowering nutes could make them flower quicker. He's just dying to know when they're finally going to bud because they're getting quite big.

don't panic they will flower when they are ready. i have 9 blue cheese and none of them are flowering yet. i can see a few sites which i think have those little white pistals but no buds as yet at all. give it another 2 weeks and they will probably be well into flowering.
changing nutes won't make them start to flower. the flowering nutes just give the plant the correct amounts of nutrients they require when flowering.
have a close look at the bud sites and i'm sure you will see some pre-flowers or something. they will flower soon.

If he's in a rush and not overly concerned about neighbours, he could induce flowering by blacking out the greenhouse every 12 hours using a tarpaulin or something, but probably best to let nature run its course tbh, shouldn't be much longer now the dark evenings are drawing in.

If you check out my grow you will notice I am growing 1 indica dominant strain and 1 100% full Indica.

Neither have started flowering yet.

funny that, i was just wondering the same thing, my outdoor plants are budding up lovely but the tunnel plants are nowhere near, wheras i expected them to be the other way around i'm sure they'll get there in the end gg xx

Would not worry caner.I live in the south west and went out and checked on are outdoor grow which is cheese and afghan kush I fed them when they where small but just let nature take care of them from then on.there are a few White hairs just coming out now.