I am rather new to Daylilies my self, but I have seen two kinds of rebloom in my garden, instant rebloom, were the rebloom scapes from the same fan start growing before the original scape is done blooming. I have noticed this year that some are so close together, that it seems both almost start, and bloom at the same time, others started after the original scape started blooming. I am seeing much more of the instant rebloom this year, but I have added many plants registered with it. The second type of rebloom I see, is what I believe to be normal rebloom, first scape comes up and blooms, and then there is a rest period before the second scape comes up. I have had a decent amount of this type the last couple of years, but it is so late in the year that the weather is cold, and what few blooms I get don't look good, and most are killed by frost. This is why I have added so many, and am hybridizing for instant rebloom. I have heard of constant rebloom, and have Stella, and Going Bananas, that seem to shoot up a scape here and there after its initial bloom, but I'm not sure it's rebloom, or if a few fans just shoot up new scapes periodically through the late summer and fall. These are just my observations over the last few years, in my own garden. There are many expeireanced Daylily growers here that I'm sure will have lots more info for you.
