beginner question

[Zeedman]

To answer the original question... planting onions, garlic, shallots, and walking onions side-by-side will not affect their culinary qualities. For seed saving purposes, shallots, onions, and walking onions are all A. cepa... so provided that you could get them to flower at the same time (and that is a big 'if') they could cross. There are amateur breeders on other sites attempting such crosses with both walking onions & potato onions, and it is not easy to do.

If your intent is to save pure seed from the onions, keep in mind that aside from a stray bolting (which I wouldn't recommend saving seed from) growing onion seed would be a two-year process. If any other onions were blooming at that time, you would just need to snip off their blooms before your seed onions began flowering.

[ChiliPeppa]

Thank you Zeedman for the helpful info.