i was gonna buy a 150 watt hps for veg gonna be doing one plant my idea was to veg it than put it outside for flowering will this be a good idea
AS long as they get sufficient light outdoors and the days are long enough then yes they will flower just fine. Why would you veg with a hps though and not a MH? IF I were you i'd veg under some 6700k cfls and flower under the 150 watt hps
If you are in the northern hemisphere above the tropics, don't start now. You won't be able to move it outside until probably April/May, and you don't want to be vegging it under a 150w HPS for 7-8 months.