I haven't been able to bring myself to spray for rust either, for the most part. And when I did, it was only with Dawn (and one time, a year ago, a bleach solution), and only after cutting back foliage. Now I've moved up to trying Serenade, which at least is a biological spray. I'm dubious how effective it will be. (Obviously, I do not use systemic sprays. For reasons I won't go into, I have a strong bias against casual use of (non fertilizer) chemicals in the garden.)
I am surprised that you have had gophers eat daylilies; that has not happened here. In any event, I defy the gophers to chomp their way through the redwood roots, and then the tree barrier, to get at the seedlings. (Fwiw, none of us has ever seen gopher holes anywhere near that part of the garden... probably because of the tree roots.)
Your seedling bed setups sound rather more sophisticated than mine, what with injectors and tar paper and such. We built our beds out of untreated cedar, and they were designed with ease of dismantling in mind (because we will probably have to dig tree roots out again, and just in case the seedlings are harder to get out than I expect, it will be easier to not have the 4 board walls of the bed in the way). I don't care if the cedar eventually rots; I'm just happy, at this point, to have moved out of the tree pots.
I understand very well your point about poor opening; that, along with rust susceptibility, is one of my chief peeves with daylilies. Two seedlings which did not open well this week were from 'Arctic Lace' x 'Ballerina on Ice'. 'Ballerina...' is rumored to be a CMO, but I am not entirely convinced about that. I will concede, however, that one bloom was open the same day as one of the seedlings, and at least 'Ballerina...' did eventually fully open (although it took until afternoon to do so). The 'Arctic Lace' cross seedling never did.
As for other aspects of hybridizing... my interest (apart from daylilies that are rust resistant and whose blooms open well) is largely in tet polymerous daylilies, so I know all about challenges.
I think I am getting a handle on that, though. I hope.
Sometimes I will admit that the challenge is
not fun
, so sometimes I make some odd crosses for other things, just to see a little success in
something. Regardless, the seedling patch surely helps keep life interesting.
