Police say a grower could be responsible for the theft of more than $10,000 worth of cucumbers in Adelaide's north.

There have been 12 separate cucumber robberies during the past three months, the most recent involving 150 bags on Tuesday night.

Chief Inspector Kym Zander says detectives are working with the Adelaide Produce Market to try to solve the case.

"We're looking at the possibility that it may be a grower that's had a failed crop and he's substituting through theft, or it may be you know somebody that knows cucumbers are being grown, they're ready for picking, and they're taking the cucumbers and then selling at those weekend markets across the metro area of Adelaide," he said.

Inspector Zander says the thefts are challenging for investigators.

"It's certainly a unique theft and the volume is something that we're having difficulty establishing where they're going," he said.

"It's obvious or evident that it is somebody in the know to establish which glasshouse is growing cucumbers, tomatoes, etcetera.

"We find that the cucumbers are being picked, they're being either packed in bags or in buckets ready for the market the next morning and when the growers turn up with their vehicles the glasshouse is bare."