what causes bull necked onions
Thick neck in onions. Â« on: July 31, 2012, 19:08:10 Â». This year a lot of my onions both main crop and over-wintering varieties have suffered from thick neck. Looking up the complaint on the Internet I've come up with the following suggestions as to the cause of thick neck.One site suggested that a lack of phosphorous could be to blame.One site suggested that planting too deep could cause it, and one site said that too much compost is the cause.ooking up the complaint on the Internet I've come up with the following suggestions as to the cause of thick neck. One site suggested that a lack of phosphorous could be to blame. One site suggested that planting too deep could cause it, and one site said that too much compost is the cause.