Hi they are greenish canes, at one end they are quite dry and brittle so I just pulled around the whippy end to make a loop and tied them together. It's not very high tech so no steam involved
Yesterday I showed my neighbour and one of the strings came undone - good news is that the cane did not revert to straight but just made a wide curve.
Hope you can see from this picture, the canes are quite thick and even though all the curves won't be equal I am hoping the effect will be good and I can attach the straighter ends of the canes to the legs of the arch.
Nora