Backyard gardens seems a bit broad whereas the rest focus in on a certain subject relating to gardens.
There are three main leadership styles that are widespread known.
The first one is the "Laissez-Faire Leadership" in which consist of minimal direction and supervision. One disadvantage of this kind of leadership is that the control could get lost by the direction and the response of employees does not meet the expectations of the job or the project.
The second one is the "Autocratic Leadership", which has been traditional across the years. This style consist of a constant supervision, which can cause stress on the employees and lack of creativity and propositivity by the team.
The last one and balanced one is the "Participative Leadership" in which it is intended to be in the middle of the two firts approach, giving to the team the freedom of use their own initiative but having at the same time a guideness and a control on the project. The disadvantage is that the balance is not easy to manage and either the team can get lost on guideliness or the leader can restrict in some way the initiatives of the team and this can lead to demotivation.