Not really, not without more info or a photo - possibilities include someone's spilt something over it, you've sprayed it recently with something, its got a heavy infestation of aphids, maybe scale insects, its being dripped on by overhead trees or shrubs...

Or possibly honeydew from aphids - has it got any signs of greenfly?

Thank you for answering, I have washed it with soap and water and rinsed it, I won't know if it will work (sounds more like washing a car! ) Until it dry's and that's not going to be for a few days! There is nothing spilt on it and no aphids or greenfly, I shall post a pic of the results its out side the front door so it needs to look nice, thanks again.

The residue has gone and its full of buds, rinsing the plant has cleared it.