This is a commonly used English expression which has been used for many centuries. It does not relate to bushes and is used as a metaphor.
The expression is usually said to someone to tell them that they are avoiding the main topic and not speaking directly about the important issue. It is often used when someone feels the other person is too embarrassed or uncomfortable to talk about what they need to be discussing.
The expression can be dated back to 1440 in the medeival poem Generydes – A Romance in Seven-line Stanzas which writes “Butt as it hath be sayde full long agoo, some bete the bussh and some the byrdes take.” The expression derives from the fact that in bird hunts some of the participants roused the birds by beating the bushes and enabling others, to catch them in nets. So therefore the “beating about the bush” was the preamble to the main event, which was the capturing of the birds. The phrase is used with the words “about” and “around” interchangeably and the general rule is that it is used with “about” in American English whilst it is more commonly used with the word “around” in British English.
An example of the usage of this expression can be found in Albert Camus’ novel The Fall which writes “Let’s not beat around the bush; I love life — that’s my real weakness. I love it so much that I am incapable of imagining what is not life.”