White powder on conifer bark?

[greenvalleytrees]

I have just been to look at a leylandii which has what looks like thick, white powder on the surface of the bark, just on one side of the trunk, from the base up to about 3ft. The bark is not falling off. There is also a little patch of the powdery growth in the fine dead growth on a conifer hedge which is about 2-3ft behind. Any ideas?

[Lazurus]

cocaine, ketamine, crack, smack. See lots of humans with similar symptoms around their nasal area

[greenvalleytrees]

The wife just said did next door get raided and throw their stash over!

[inthewoods]

Lick it or sniff it... Should give you a better idea of what it is ;-)