How can you age a rendered wall?

[Skyline]

6 months ago we had part of our house wall re-rendered by a builder. The house is quite old so he used lime to get the render the same colour as the existing mortar. Unfortunately when it dried it turned out to be very bright and we would like it to look more aged. Someone told me if I painted live yoghurt all over it would encourage Lichen to grow, thus disguising the newness and brightness. It didn't work, although it was Winter when I did this so it might have been too cold for the Lichen to form. Can anyone suggest another way to age unsightly render, I'm loath to paint it with masonry paint because that will draw even more attention to it. Many thanks in advance.

[rekstout]

It should age pretty quickly, especially now that it's growing season - we had to render an existing modern brick extension to our house because it wasn't in keeping with the rest of the house which is 200 years old - looked a bit wierd to say the least. That was 12 months ago and it already looks pretty aged after a full year.

Patience is all I can suggest. Liquid Manure works well for aging stonework but remember that moss and the like may give you a damp problem as it retains water against the wall. Clematis and suitable ivys would certainly break up the expanse of stark white and should grow like wildfire if the weather holds like this.