if you're prepared to used TMs then tropius can learn a pretty broad range, mostly grass but ground, flying, poison, 1 steel and 1 bug.
cacnea/ cacturne is better though for a wide range of moves.
By moving clumps of grass in pokemon emerald.
You an train Pokemon in the grass
In Emerald, Pokemon can be found in Grass, Water, and Caves. There are 385 Pokemon in total.
grass/posin
in the underwater grass but he is rare.
I would just say to get a variety of types. I suggest flying, fire, water, grass, electric, and psychic, or something similar.
get at TREEKO! TREEKO HAS AND ALWAYS WILL NOT ONLY BE THE BEST GRASS POKEMON BUT MY FAVORITE AND THE ABSOLUTE BEST!
Mt. Pyre Grass
leve her and go live at your freinds house
Gligar is in the grass near cycling road if you insert Pokemon Emerald. In Platinum, the dongle feature is not nessecary.
Underwater, in the grass outside Sootopolis City.
Roselia, Bellossom or Sceptile.