Rotten Potato Smell in Garage?

I've moved into a condo with detached garage. The previous tenants seem to have used the garage as a potato/veggie storage. The garage's semi-finished walls and cement floor smell like old stored/rotten potatoes. The landlady tried everything to get the smell out, but now with high temperatures and humidity the smell is in full force. The interior of my car and trunk are starting to stink.

Any ideas to clean this foul odor out would be greatly appreciated. Thanks in advance.