Heat Treated Onion Set Problems

Tried heat treated onions from Marshalls this year and the varieties were Fen Early, Hytech F1 and Hyred. Heat treated onion sets are meant to perform better than standard sets by having reduced numbers running to seed. However I would estimate 60% of the Hyred and Hytech F1 went to seed and 10% of the Fen Early. I can only put it down to the weather but I would of thought cool damp conditions would be OK for onions.

I will try onion seeds next year instead of sets. Anybody got any recommendations for a white and red variety along with any tips?

I hav e grown Hytech heat treated onions several times with good results and no bolting. Heat treatment is supposed to kill the embryo flower in the onion bulbs so we must presume that the treatment process did not work.

If you are sure they were supplied as heat treated I would contact the supplier and complain. If there was a batch that missed the heat treatment they will probably know about it already but they may not if nobody has complained.

Even if they were not treated that % of bolters is very high. Mine have always come from Suttons who do not send them out until April because the for heat treatment they are held at a high temperature for about 3 weeks.