start the plants inside for the first week or so, then transplant outside, if you can't do it this way thats fine.
I would suggest spacing them out so it looks like they've grown naturally there.
less of a chance someone will notice them if by chance walking by.
if you get 'ready to grow' soil, dig a hole 2ft down and wide and mix the old soil (25%), with the soil you have (75%) to conserve on the soil, if not, it would cost a whole lot to fill up 10 2"x2" holes.
if you have the cash, I would.
mound the dirt on the top, it will settle within the first 2 waterings, or rains.
hope some of this helped.
good luck man