Cuttings from a bunch of cut flowers

That is quick Val for a rose, well done

I've rooted roses from bunches of cut flowers on several occasions, this is one that I took last year, flowering now


I've also rooted roses easily from plants growing in the ground, in both cases cuttings of about 12 inches in length and the thickness of a pencil seem to do well. Mine have always been struck in compost, take a deep pot, put some sandy compost in the bottom and then fill up with a good general compost, take your cutting with just one or two leaves left on the top and dip in some rooting powder and push in to the compost until there's just an inch or two sticking out. Water and then leave in a sheltered spot out of direct sun, done between now and the autumn they should be root reasonably quickly

 

I have found that getting plants that root in water to transition to soil, when potted-on, can be a challenge so you might want to take extra care at that point. I don't know what types of compost give you the greatest chance of success though.