should half stem roses be dead headed?
Are you talking about Half Standard roses? If so, yes. If the grafted on rosebush is a floribunda rosebush, trim off the spent rose bloom down to the first leaf cluster with the cane it is on where the cane appears large enough in diameter to support a new bloom. If the grafted on rosebush is a hybrid tea or grandiflora rosebush, trim the spent bloom off down to the first 5 leaf junction with the cane or at least to a good strong three to four leaf junction. If the grafted on rosebush is a shrub type rosebush or miniature rosebush, trim off the spent blooms down to their junction with the stem they are on where the multiple blooms formed. Watch for new growth coming on. If it is below the place where you originally pruned off the spent bloom, you may need to go ahead and prune off the canes down to just above the new growth. Link:https://www.roses.co.uk/half-standard-roses