Sounds like too much water. Either stored with too much water or watered too much after planting. They rot and will not sprout.
"Look, let me explain something to you. I'm not Mr. Lebowski. You're Mr. Lebowski. I'm the Dude. So that's what you call me. That or His Dudeness... Duder... or El Duderino, if, you know, you're not into the whole brevity thing." -The Dude