Hi Nikki and welcome to GoY. I hope you haven't raised the level of the soil right up to the flowering cherry. Trees do not like the level of the soil to be raised round their trunk and you run the risk of the tree dying. Very little will grow in amongst the roots and climb up the tree.

Whoa! How deep is the raised bed? I'm worried about this - as MG says it's not good for the tree. Better have a rethink, Loulou.

Apart from the comments already made concerning raising a bed around your cherry, I can't see any purpose in training a climber onto a flowering cherry and I don't think the final outcome will be pleasing. If it was a dead tree it would be a different matter.

The difficulty with cherry trees is they loathe root disturbance, and are fairly shallow rooting, spreading out long horizontal roots which often become visible over time. Agree with all comments about raising the soil level over the roots of an existing tree, not a good idea at all. And now that the tree is established, it is not a good idea to get anything planted nearby - I have certainly grown clematis up a cherry tree on many occasions of planting, feeling that cherries look quite boring when not in flower, but always planted them at the same time, when it doesn't cause a problem.