It depends on the vegetable.  Washed produce will spoil more quickly because of the moisture that is left on it.  And, when it comes time for storage veggies in the fall, it is best that they be stored without any washing.
However, all loose salad greens are washed as are bunch carrots and beets. This means your kids can snack on baby carrots on your way home from pick-up.
We will provide more storage tips and information on washing veggies as the season unfolds.  If you have any questions about whether you need to wash a specific item, ask when you pick it up.