It's almost so literally applicable to everything that it seems like a fundamental principle.
By gardening, I mean something like... tending lovingly to a system of interconnected complex tree-like structures.
Is personal life anything like that? Yeah, because friends and loved ones are plants with roots and offshoots, subterraneously connected to one another yet also independent life forms, dependent on light, warmth, and nutrition to stimulate their growing complexity.
Is work anything like that? Well, look at GitHub and say it isn't a garden of interdependent tree structures.
There's growth but also death and decay, and both are necessary. My little palm tree always has a couple of leaves that are dying, and for its health, I have to rip them off. Programs too need pruning—and relationships too.