origin of the expression: kick things into long grass

To understand this British expression, you have to envision a football pitch in a rural area where only the pitch itself and a bit of touch (the field beyond the white lines) is maintained.

Football pitch in Marsden.

If one kicks the ball into the grass — or even better, into the wooded area in the background — not only does play stop, but a new ball would usually be brought in to continue uninterrupted play and the first ball "forgotten".

Another source suggests a derivation from golf, not football or rugby. This would add an element of subterfuge and cheating to the expression.