Will I need a HPS later

[Holly]

I bought a 400w MH ballast/bulb/reflector for the 11 plant system. Seems pretty nice, the heavy ballast is separate from the fixture (I don't have to hang it.) However, I'm a little uncertain about their applications. Will I need a hps later in order for the plants to bloom? I thought I'd be ok with just the MH for vegetables, herbs etc. Will my flowers be able to bloom under MH (carnations). Lighting is big $$ and I didn't want to invest in both. I live in the northeast and am planning on starting indoors in the winter and than moving to the plants outside on the deck in Late Spring and Summer.

New 2 Hydro Holly