What you will need:
Some polystyrene ceiling tiles.
Green paint
PVA glue
Flock

Step 1
Draw whatever shape hill you want onto of polystyrene ceiling tiles.

Step 2
Cut the shape out.

Step 3
Sand the edges until it is smooth and looks hill shape.

Step 4
Paint you "hill" green.

Step 5 (optional)
Put glue all over your "hill" and scatter flock all over it.

What you will need:
Some green pan scourers
Hot glue
Scissors

Step 1
Fold one of the scourers in half. If you like the height leave it as it is but if you would like the hedge to be shorter cut a bit off the bottom till it is the required height.

Step 2
Do the same for the rest of the scourers.