More than 40,000 plants are spread out in green houses that cover the 10-acre property in the 2500 block of McAllister Street in the Greenbelt neighborhood. Riverside officials said the marijuana grow operation is compared in size to a city block.
Neighbor Scott Albertsons said the former nursery was sold six months ago.
"They came in and put up this new fence, which you couldn't see through. We all wondered what that was about," he said.
He said it soon became apparent what the new owners were up to.
"We didn't call in. We figured a policeman would drive by and smell it because you could smell it, especially in the evening and early morning," Albertsons added.
An anonymous tip led Riverside police on Thursday to the massive cannabis farm with an estimated street value of $20 million.
The Riverside Police Department said it took officers 24 hours to collect plants along with thousands of pounds of fertilizer and pesticides from the property. Investigators found plants in various stages of growth.
No one was immediately arrested because it appeared the home was abandoned as police were preparing to move in. Several vehicles, forklifts, and tractor were impounded and will be put up for asset forfeiture.
The community where the grow operation was discovered is rural but many were surprised anyone would risk planting marijuana in the neighborhood.
"We were concerned about what was going on because, frankly, in our neighborhood here, that doesn't occur," said a neighbor who asked not to be identified.