Depending on your needs they can be cultured several ways. I used to have six of seven fish shipping styros filled with 3 to 4 inches of moist dirt and kept on the floor of the basement. I fed mine bread with plain yogurt smeared on both sides. I had a sheet of plexiglass covering that and a lid on the culture. Once rolling, these cultures would meet my needs for the small hatchery we had. 1 box used once a week provided plenty of worms...use a different box each day.
Today I have downsized and culture the worms in those Glad plastic containers stored in a cooler with an icepack. The worms like a 50 to 60 degree dark environment.