That could be... he could be going after them because the ground is freshly dug, or because they smell like Rosie, or he might dig them up anyway. My dogs found a lot of old bulbs that were planted here when we moved here... they weren't bad diggers, I just kept seeing them turn up. Dogs is dogs, I guess :~) I wouldn't try to have a lot of cultivated beds unless I wanted to put a fence around it, just cuz they'll step on everything at the very least. :~\
Sam's never out long enough to dig up bulbs. But he does step (and pee) on everything else...