Wrong time of year to be spraying anything. Most herbicides are ineffective unless applied during active growth, which just about anywhere in the US is not in late December!

Most herbicides also cannot determine between a weed or a more valued plant, so unless carefully shielded from any spray drift, shrubs will be just as vulnerable to damage as the weeds.

Manual removal - which can be done at any time of year - will always be safer than any herbicide application.