Hi iome_miageta,

Have you used paint effects before?

They have vines you can paint onto objects there, you first have to select the object you want the vines to be covering, then go into the rendering menu set, and at the end is paint effects, in that drop down menu you will find "make paintable" select that with your geometry selected, then go back into the paint effects menu and select "get brush".
The visor will open and under the plants tab you will find vines and other assorted plants.

You can only render paint effects with the maya renderer not mental ray, to render in mental ray you have to go into the convert menu set and select "convert paint effects to polys", making sure you click the little box on the right and setting the poly limit for the conversion high enough to convert it properly, this will push your poly count up a lot if you use it too many times in one scene.

Hope that's of some help!

Good luck and happy modeling!