For a business like landscaping the best thing that you can do is advertise on Craigslist and on BackPage.com
They're both free and they'll drive actual customers to your website.
If you want to do things for SEO purposes then as noted above, find the keywords for your business using google adwords tool (Start with <city you're in> Landscaping - it'll suggest things from there and show you how many searches those terms are getting.)
Once you understand your keywords, you can use them to link back to your site from other sites like social media and social bookmarking sites. Delicious, clipmarks, yahoo buzz, digg, facebook ... start linking to your site from anywhere that will let you put up some HTML (OK, maybe not anywhere ... but almost, keep it relevant)
I have a free report with 6 traffic tactics you can download. Hope it helps.