Yes @KCMM09 a star jasmine would love that south facing wall and the white flowers would pick up the white roses.It's a bit late to be moving things now but if you water it well beforehand and dig out as much of the root ball as you can and plonk it carefully in a ready prepared hole improved with well-rotted manure, check it's at the same level as before, back fill and water generously. You'll then need to keep it watered all thru this first growing season.Walls suck up lots of moisture and also make a rain shadow so do enrich the soil, don't plant too close to the wall and do water. 15L a time poured slowly so it soaks down. Do this weekly till next autumn especially in hot and dry spells but not if you have biblical rain.
My favourite combination of design and planting - formal, structured, hard landscaping with straight borders stuffed with a riot of blowsy cottage garden style planting.Hardy, geraniums, hostas, ferns, geums, alchemilla mollis, dicentra, brunnera - just some of my own 'go to' low height plants which do well in my own north facing garden.Just one note of caution - if those are buxus topiary dotted around, be a bit careful about allowing plants to flop on them. Apart from spoiling the effect of the topiary it can also be a recipe for the introduction of box blight. Try to surround those with plants which support themselves (eg hostas and ferns)