Small Shrub is an inexpensive early-game decoration that positively influences local Desirability in a small range. This building provides a 1-2% desirability boost at maximum separation of 3 squares between this structure and a Shelter)
Basic Strategy
Given the relatively low desirability impact (1-2%) and range, it is best to only use these buildings decoratively (as the name suggests) to liven up public spaces or in residential spaces where more-advantageous buildings will not fit.
Additionally, given comments by Crate's developers about over-use of small, desirability-influencing buildings causing game lag by calculation costs, it is not recommended to excessively build this structure for the sake of filling space (e.g. cramming hundreds of copies into a residential area)