Hi Dave--Not sure what would cause it unless it is newer canes on the rose bush. Leaves and blooms are heavy and will cause them to droop. I take yarn or garden twine and tie them upright to a support pole. Usually within a season the cane can keep itself upright and I cut the yarn/twine and remove the support pole. I have had to do this with Althea also. Your hibiscus whether tropical or hardy can temporarily supported. Have a joyful week!
