Kiley Swanson picks cucumbers with help from his dad, Charlie, inside their high-tunnel greenhouse on the family's farm near Ogden. The Swansons grow vegetables for several summer camps along the Des Moines River, in addition to their on-farm stand.In the summer when Kiley Swanson gets off work from his full-time job at a local farm, his day is just beginning.

Swanson, 25, drives down the road to his parent’s farm near Dayton, where he and his dad, Charlie, and mom, Judy, grow a one-acre vegetable plot.

The Swansons spend their afternoons picking tomatoes, cucumbers and sweet corn; digging up onions; and planting a fall crop of lettuce.

If they need to work past sunset to fill an order, the Swansons wear headlamps and bring a shop light out into the field so they can...