Shrubs that grow out of control can cause damage to your home. During winter storms, wind and rain rub the shrubs against your side and can cause damage to the side as well as your screens and windows. Shrubs are also a magnet for insects which can use the proximity to your home as way to trying to get in. You can minimize your pest and insect problems by keep shrubs trimmed away from the siding.
Make sure you trim your shrubs about 6 to 12 inches from your home. This will keep them from rubbing up against the house especially during windy and rainy storms. This is especially important with wood siding and wood trims around windows, but it is still good advice no matter what the exterior of your home is made of.
Here is a video from Homemadesimple.