hi everyone! i live in pasadena (hardiness 10a, climate 21). I'd like some kind of colorful hedge growing along my backyard's 4' brick wall which has trellis-like bars/fencing over the top. my original thought was various colored bougainvilleas because i LOVE vibrant year round color. but i'm worried about the thorns and aggressive nature of this plant requiring diligent pruning. any suggestions for friendlier alternatives? thanks in advance!