i grow carrots in 50gallon tubs on the roof of the garage so they are 12 ft of the floor and tubs are nearly 3ft high if carrot fly can only fly at 2ft high how are my carrots being decimated by carrot fly maggots ps the tubs i grow onions with the carrots arnt affected
Certified GKH Gardening Expert
There is a possibility that the soil or carrots were infested prior to planting or at planting time. This would make it to where they will treat your containers as "ground".
This article will help you to take care of this issue:
Interplanting with onions is a really good way to keep away pest insects. The chemicals within the onion are natural pest controls.