I JUST STARTED GROWING INDOORS A COUPLE OF MONTHS AGO,BUT I HAVE AN IDEA OF WHAT ANSWER TO GIVE YOU.START OUT WITH A CHEAP 4 FT SHOP LIGHT,THEN GIVE THEM AT LEAST 25 WATTS SQ FT METAL HALIDE.OF COARSE THE MORE LIGHT YOU GIVE THEM THE FASTER THEY WILL GROW.I USE A LOT MORE THAN THIS THOUGH.I STARTED OUT PROVIDING THEM WITH 53W PER SQ FT AND NOW AS OF YESTERDAY ,AM UP TO 66W..I HAVE PICS OF MY SETUP,START TO NOW,IF YOU WOULD LIKE TO SEE THEM LET ME KNOW.SCOTT

I've been starting basil under fluorescents every few weeks to ensure a steady supply for my outdoor garden. (Agrosun bulbs work much better than ordinary cool-whites, and more-modern T8 or T5 fixtures may work better still.) Indoors, as zipper says, you can do the same thing, moving them to metal halides rather than to sunlight; that would let you grow them pretty tall. Or you could keep several flats of small plants under fluorescents, cutting them back a few times, and then harvesting the whole plant when they get nice and bushy.

You might be best off, though, buying or growing your winter supply outdoors now, and chopping and freezing enough of it in olive oil to last you till next summer. In fact, just laying it flat in Ziploc freezer bags, pressing the air out, sealing it, and freezing immediately does a pretty good job of preserving basil; pull leaves off and chop when you need them.

I have grown a basil plant to about 12+ inches so far under two fluorescent fixtures. 2-3 48" Fluorescent fixtures (with two bulbs each) close together can grow vegitative plants fairly well, it won't grow it super fast, but it will grow. The regular cool white bulbs work fine and are very cheap.

-Curtis

Basil is a windowsill herb. That means it can grow without supplemental light in a sunny windowsill. Of the herbs suitable to windowsill growing basil is one of the more light greedy herbs so if you don't have a great spot for it then artificial light will do great.

Which is the 'best' light? Hooboy! Well, I guess a MH light is the best for vegetative growth simply because they throw out a lot more lumens per inch of tube than anything else, but they also get hot and aren't cheap, particularly if you buy the drasticly overpriced 'grow bulbs' instead of the regular kind the hardware store sells.

Skip the HPS as it is better suited to getting plants to flower/fruit and that isn't what you want from basil.

Floros will work just fine for basil and are easily available.

I tend to agree with nygardener though, basil is pretty easy to grow outside and it freezes well so it isn't necessary to grow it all year to have some during the winter. Up to you though.

I grow sweet basil under a 150w HPS and they are growing quite well! I did a short write-up about it on my blog, and posted pictures as well. I think I would like to try MH, because I know about the different phytochromes and their respective spectral efficiencies, but if you only have HPS, don't think that you can't grow vegetatively!

Here is a link that might be useful: http://dotcadot.ca/blogs/jean-paul/dwc-sweet-basil-150w-hps

I grow basil under flouros and they do very well since they get the vegetative light they need.

Running in a deep water culture hydroponics systems keeps optimum efficient and faster growth / larger harvests than soil as well.

The lemon smells so good!!!

Here is a link that might be useful: My Indoor Growing Adventure

My wife is Italian so we make lots of pesto. I normally grow basil among my landscape plants. This year I am putting in a grow light system and intend to grow basil well before I can move it outside.