Is it too late to top my plants? (pics)

Hello All, This is my first grow and I was wondering if it is too late to top my plants. I vegged for 5 weeks and it is now day 5 of flowering. I've got 16 plants under a 600 watt hps cool tube and even in the first few days they are growing more than I anticipated. One of the females is already pushing 2 1/2 feet tall. Any advice would be appreciated. Thanks in advance as everyone here has been very helpful

yea sorry to late to start it. in flowering you want ure babys to concentrate on forming buds not starting new growth. i mean nothing would happen to em its just the buds would be small and proabably shit.
peace and dont worry bout it they look amazing

Yes, if they were still in veg, but as soon as the go flower, you really dont want to be cutting on your plants, if hieght is an issuse you can bend LSD......