Gardening

I have been feeling guilty lately. I have to start off by saying I love my yard and all that it offers. Lots of grass, little amounts of flower beds and a side of just concrete which is flat and great for ball and riding bikes. Oh yeah and it is fenced. Lately though I have been feeling like I am letting the world down by not having a garden. I feel like I am somehow not contributing to "helping the earth" I mean my goodness even the white house is getting rid of some of there grass for a garden.
But, then I go out there to play with the kids or weed and I am so happy with the usefulness of my yard. It really serves it's purpose for us. Room for the swing set, trampoline and yet we still have room to play ball and all that. If I did put in a garden what would I have to give up to make room for it? The good places for it would be where the swing set is or right in front of the shed which means that balls would land on it all the time. I LOVE grass. It is soft to run on and fun to lay in and look at the sky. So my question to you all, is it bad that I don't garden and do my part to help out. If that is what I am truly doing.