Grafting works very well if you know what you're doing. It's an advanced horticultural technique that involves fusing genetically distinct but compatible, complimentary shoots and roots together. The rootstock usually imparts benefits like vigor, disease resistance, short stature and other benefits to the shoots (also called scion) of plants with desirable ornamental features but less than desirable resiliency. Grafting is also used to do goofy things like graft four different apple types on a single tree or sculpt branches into shapes.

I've heard that roses are grafted on a regular basis.