I dont understand why anyone would grow onj their own property in the US....especially if you have close neighbours. You get caught (which sounds likely if your 20 feet away) and your screwed. They will take away your property (proceeds of crime) and then feed you to bubba for years. With guerilla your plants are nowhere you would have to worry much about smell and you have plausible deniability if and anonimity if they are found.

JMO

Good Luck!