Zebra is a black-stemmed naturally occurring mutation of 'White Ball' (F&E White Out). They grow to about 3x3' and feature somewhat large leaves with long leaf internodes. They're not very winter hardy and bloom on old wood only, from what I've seen this far (two seasons).

Consider moving your daylilies elswhere or giving them away / selling them! The tall orange ones will easily re-root in disposal areas compost piles, hence the term "ditch lily".

I wish Zebra bloomed on new and old wood. I will think about it some more. I do want to thin out the day lilies