I found this website, but doesn't have much info on Calvert. It does have listings for lots of farms in the state, but I didn't specifically see corn. Maybe there is a contact on the site that could help you in your search. Love the local corn! We have some just about every nite.
Where in Maryland to find pick your own farms and orchards for fruit, vegetables, pumpkins and canning & freezing instructions!
You could try:
Linda's Plant and Produce , Port Republic , MD
Corn, cantaloupes, watermelons, tomatoes, peppers, eggplant, cut flowers, potatoes, sweet potatoes, pumpkins, squash, cucumbers, mums, hanging baskets, bedding plants, and vegetable plants. DIRECTIONS: Produce stand: .25 mile off Route 4 on Broomes Island Road. Greenhouses: 4 miles off Route 4 on Broomes Island Road on left.
website:
http://www.calvertag.com/Farms/Lindas.htm
phone: 410-586-1443
address: 5980 Broomes Island Road
Port Republic, MD 20676
UofM Extension:
Maryland Agriculture: Green Industry
Or, maybe Chesapeake's Bounty in St. Leonard can special order for you from the farmers that they get their goods from.