I have been happily growing Moussaka here in zone 3 for a number of years now. This is the most amazing daylily I have for longest bloom / rebloom period. In fact, I posted a comment about Moussaka a year ago...
"It produces multiple scapes with many buds per scape and begins blooming by the 2nd week of July. That may not seem like much but it continues blooming well into August - and still bloomed in September.
Moussaka was the ONLY daylily in my gardens that was still putting out flowers in the 2nd week of October, giving its last blooms of the year during the same week I was planting my Asiatic and Oriental lily bulbs for next year. Absolutely amazing."
I stand by that comment, but have to add: it bloomed even more heavily this past summer, having another year during which time it has matured even further, multiplied to a larger clump and cranked out scape after scape after scape, each one loaded with buds.
Several garden sites claim "Blooms are produced abundantly, a 3 year old plant can have 200 blooms or more in a season!" Yes, in my garden - that is true!
It flowers continuously and rebloom scapes begin appearing before the first scapes have finished blooming.
What do I do differently here? Nothing. All of my gardens get a dose of Milorganite in the spring each year, and I am growing in compost dumped casually on top of cardboard laid overtop what was previously grass & weeds that passed for 'lawn' on top of a sandy base. That's it: secret exposed. No fancy prep, no miracle formula. Plant, mulch, enjoy.
Moussaka does not care. It just grows. And blooms... and blooms (and blooms). It starts early and blooms into October, surviving and ignoring the first five or six frosts of the year, finally dying back in mid-October.
I have been working with this daylily to see if I can grow some cold-climate late bloomers and the first seedlings from it should start flowering this year. I will keep you posted.