Hello, The common orange daylily can quite aggressive spreading from root and by seed. Hand digging out all of the roots without leaving any tiny piece is a daunting task. Alternative control measures are to cut or mow the lilies down, then place cardboard or thick layers of newspaper over them, then a layer of mulch 3-4 inches deep. Cut off any shoots that work their way though. Another method I'd to spray entire bed of daylilies with a herbicide contains glyphosate, such as Roundup. You can combine these last two by using herbicide first on full length leaves, wait two weeks then cut it all back, then place the cardboard and mulch. Regards, Carol Quish