In a medium bowl, combine sour cream, mayonnaise, milk, lemon peel and juice, garlic, onion and dill. Cover and chill for at least 4 hours or up to 1 week.
If you like, cut cucumbers in half lengthwise. Cut both ends to a point. Cut a very thin sliver off the bottom of the cucumber so it can sit evenly. With a melon baller, scoop out about 3 scoops of the middle. Place desired fresh vegetables in the boats. Serve with dip. Or, serve fresh vegetables on a platter with the dip.