Cull onions
Cull Onion Disposal Deadline March 15
The deadline for the disposal of cull onions in Ada, Canyon, Gem, Payette, Owyhee and Washington counties is March 15, 2026.
Under the Rules Governing the Disposal of Cull Onions and Potatoes (IDAPA 02.06.05 Subchapter E), all cull or waste onions not suitable for human consumption must be disposed of by an approved method prior to March 15 each year. After March 15, onions that are sorted must be disposed of within one week.
Idaho State Department of Agriculture (ISDA) inspectors will monitor disposal sites to ensure that culls are properly disposed of. Approved disposal methods include pit burial, feeding, composting, spreading, chopping and shredding. The University of Idaho’s Best Management Practices for Pit Disposal of Cull Onions is referenced in the rule and is available through University of Idaho Extension.
The purpose of the disposal deadline is to protect the onion industry from onion maggot.
Onion maggot is a fast-reproducing pest that damages onion crops. Its larvae feed on the roots of germinating seedlings and later on expanding bulbs, which can severely reduce onion yields. Feeding damage also provides an avenue for pathogens to rot bulbs during storage.
For more information on cull onion disposal, contact ISDA at (208) 332-8620
