Plant that will flower, spread and grow in gravel garden

Hello,

For those that have read my previous post, I have removed the very dead hydrangea from my front garden. 

It was very well established until someone cut it back. I am now looking for a replacement plant.

The area has a concrete base, plastic sheeting then gravel. No soil at all. What can I grow there that will form a nice large bushy plant, grows quickly, flowers and will thrive in such hardy conditions? It is at use the front of my house, so want something that will grow quickly and looks nice.

Am tempted to put another hydrangea there, but am scared it won't take because of the plastic sheeting.

Please can anyone advise?

Thanks again all.