You look as if you've been dragged through a hedge backwards

Meaning

Said to someone who is unkempt and whose hair needs brushing.

Origin

I'm fairly confident that this expression is of English colloquial origin. Despite searches however I haven't been able to find an English citation that pre-dates this piece in The Manitoba Morning Free Press, February 1910:

There are husbands who do their wives no credit. Before you have time to get your hat on and show them to an admiring world... they look as if they had been dragged through a hedge backwards.

More recently, the English cook and food writer Hugh Fearnley-Whittingstall's (and with a name like that he would surely have to be English) advocation of eating food from hedgerows and his unkempt hair has led to a resurgence of use of the phrase in reviews of his work.