TTS: If you read back through the archives, you'll see some good threads on elevating your online profile/off-site SEO. I'd also suggest hitting getlisted.org, put in your info, and see where your online footprint is lacking.
ShorterGrass: You'd have a tough time tying your Facebook or Adwords campaigns to the increased organic rank of your web site. Your site rose due to your location/competition. You're definitely correct that Adwords is a great way to prop your traffic up until you can start ranking your site on the first page. Once you're ranking, you can eliminate that ad spend, or reallocate it to other keywords of interest.
a guy who knows both the lawn business and web strategy