Yep! They have to be shaking, though. Trash cans are only present in the Pokemon Village and the Lost Hotel. You can find wild Trubbish and Garbodor in the Lost Hotel cans (and Rotom on Tuesdays) and you can find wild Garbodor in the Village trash cans (and Banette on Thursdays.) You can also find a variety of items.
In the Lost Hotel cans:
Every Day
Common
-Dusk Ball
-Escape Rope
-Super Repel
Uncommon
-HP Up
-Protein
-Iron
Rare
-Max Elixir
Tuesdays
Common
-Escape Rope
-Max Repel
-Nugget
Uncommon
-Calcium
-Carbos
-Zinc
Rare
-Big Nugget
In the Pokemon Village cans:
Every Day
Common
-Honey
-Pretty Wing
-TinyMushroom
Uncommon
-Big Mushroom
-Max Revive
-Poke Toy
Rare
-Mental Herb
Thursdays
Common
-Big Mushroom
-Honey
-Prism Scale
Uncommon
-Balm Mushroom
-Heal Powder
-Revival Herb
Rare
-Eviolite (oooooh)
Source: http://www.serebii.net/xy/rocktrash.shtml