Stephen: the depth of your research is staggering! I can't wait to read the book.
I'm in Canada as well (and rest-assured, Egyptian/Walking onions survive easily). One difficulty when trying to assemble a collection of various Alliums is that because many are propagated by bulbs, they are not always legally traded across national borders.
That said, this can be a good thing. I recently learned that there is a Leek Moth that is playing havoc with Allium family plants. It has recently been introduced to my region, and from talking to a friend, those afflicted by the moth have this to look forward to:
1. First stage, adult moth lays eggs on green onion. Larva devour much of the top of the onion before pupating.
2. Stage two, the second adults of the season lay eggs lower down on the plant, and the larva of this cycle devour the bulb.
It sounds very frightening, since it effects Egyptian Onions, and one would guess, perhaps all alliums.
Has anyone witnessed this scourge? Any alliums known to be resistant to these moths? Any techniques to protect favourites Alliums? (Other than hiding your onions amongst other plants in polycultures.) Should
we be looking for aromatic pest confusers for our aromatic pest confusers?