Japanese lawns aren't covered with grass. More often than not, they're rocks. So most people have gardens. Naruto and Kakashi have theirs in the front yard. Shikamaru has his in the back.

So, you're all familiar with the concept of a porch? What Shikamaru's laying on is like that, only it's smaller, and pretty close to the ground. You can step off it really easily, and it's only just wide enough to lay down on. (It's about three or four planks wide).

The garden itself will have no grass. It would have flowers, trees and bushes, but no grass...and any sprouting grass-thingies would be pulled out. Isn't that funny? We cultivate ours, and they treat theirs like weeds...