the leftovers are on route 12 where there is a tree that will need to be cut by a Pokemon that knows hm01 Cut
these are the Pokemon that know cut http://pokemondb.net/move/cut
Cut is found in the maze garden at the back of Parfum palace.
if you are going to route 12 from Shalour City you will need a Pokemon that knows hm03 Surf
these are the Pokemon that learn surf http://pokemondb.net/move/surf
Surf is given to you by Calem/Serena after you defeat Korina.
you can also find leftovers by having a Pokemon with the ability pickup those Pokemon are : http://pokemondb.net/ability/pickup
Source : knowledge
Hope I helped :)