I am quite new to this game (level 188) but putting his obnoxious comments aside, I sure would like Austin to be an environmental friendly gardener. Using weed killers and spraying the insects on your bonsai will not help the world at all. I think his secret agenda is simply spellen M.O.N.S.A.N.T.O!
How about putting some beehives in the game? And doing weeding with your bare hands and some nice (copper/bronze) garden tools?
How about planting seeds and preserving the soil?