We're having some unusually cold weather where we are, and I personally have never really done any protecting of bushes, well, really a big pot of flowers, or even pipes. What is the easiest why to try and keep the things alive (and protect the pipes, though that is a bit off topic).
Smaller bushes and plants can be covered with old towels or sheets, anything to keep the cold air from carrying the heat away...
For your plumbing if you let a small trickle of water flow it will keep the water in the pipes from shedding enough heat that it will freeze and break the pipes... :smile:KennyV