tomatoes & oyster shells

[tonymalone]

i have had in the past a problem w/ my tomatoes rotting from the bottom about the time they get ripe.

i have been told the stuff ya spray on em to prevent this is calcium, and that if ya will put some oyster shells (like for chickens) in the ground around your tomatoe plants, that it will prevent the rotting from the bottom.

anybody know anything about this?

thanks