K.B.
If it's small to medium sized toys that are the problem we have a Rubbermaid Deck Box on our patio that the kids keep their toys in. Basically it's a toy box outside. Here's the link http://www.amazon.com/gp/product/B000CFOW3O.
If it's larger ride on toys or bikes that are the problem the only solution I've found is to move them into the garage each day.
Good Luck!
K.