Hello Plot22.
We've had it on our site for a few years now. I cover mine, but as this doesn't seem an option for you, you could try what some of our plot holders do and that is to start their onions in modules at home with a view to being able to plant out this Spring bank holiday week when the miner fly's first period should be over. They say they still get a reasonable size crop although not as large as those planted earlier. Alternatively, covering some and starting some later. Hope this helps.
Regards
Bluecar