I like this one, too. I like a whole bunch of suggestions here, actually. Have to print them all out and see which one my cat sits on. 
Attention To Detail Design
Acer Spades Landscape
If you’re Italian: Yew-Need-A-Landscape
Make sure it’s sits on and not shits on please.
Eco-Edens, Inc.
Easy Eden Landscaping, Inc.
Eco-Smart Landscaping, Inc.
I love the plays on the word “xeriscaping,” but I wonder how many people would get it.
Bushco
Terransformation
Breeze
Land Scape Design. LSD! Oooooooh, pretty, man!
There used to be one over here called : Fences and Hedges (sounds like a certain brand of ciggies).
If you want more of a water retriculation focus, how about: Colonial Irrigation
It is a good idea to keep the name descriptive:
LandDesign
EarthScape Design
EarthDesign
or
AAAardvaark LandSkaping
H[sub]2[/sub]LOW (with the “L” and “W” actually proportionally smaller, albeit readily visible, in the company “low-go”)
Earth People.
The Great Outdoors
The Moving Earth
(Tagline: I’ll make the Earth move for you)
or
Slartibartfast
I have no idea but make it something good.
I was watching a movie with my son recently and the credit for the visual effects was Giant Killer Robots. My son remarked that obviously one of the advantages of starting your own business is that you can give it a cool name.
“Imagine,” he said, "someone asks where you work and you can say, “Giant Killer Robots dude, Giant Killer Robots.’”
I could see his point.
“ROOTS”, From grass to trees, healthy roots are the secret to success.
There’s a company here in town called Explosives, Inc. How cool would it be to be able to say you work there? Of course, there are also B.J. Services and the former P.M.S. Hobbycraft. Not as cool. But yes, I do want to make it good, not some uber-cutesy, schlocky name that I’ll regret in a year.
Slartibartfast? That might be the most ingenious suggestion yet. Colonial Irrigation is also good. If I started a company specializing in irrigation systems, I think I would have to go with that one.
There’s a commercial sod company that has a large field just north of Salem, Or., right next to I-5. They have a sign that says “We just keep rolling a lawn”.
SimpleScape
Lawncitecture
Easy Green
I also like The Lawn Ranger.
Lawncitecture - that’s so awkward that I love it! The Lawn Ranger - very cool. Too bad I am the enemy of lawns.