posted 3 hours ago
Maybe it's helpful to think less in terms of absolutes and more in terms of commonsense.
"Sustainable", able to be sustained, does not and should not imply "forever". Nothing is forever, and the laws of thermodynamics tell us we cannot create order in one place without creating disorder somewhere else.
Sustainable can have a human-scale meaning: if you implement this, can you sustain it without further considerable expense? Is it something there is will to do? Will implementing it once set in motion a kind of inertia so that the thing tends to "care for itself"? If the answer to these kinds of questions is yes, then it is sustainable.
I will use the example of my property: we have a mixture of grass and perennial native flower garden beds. The grass requires mowing, but we do nothing else to it. Anything further I would consider unsustainable, though even the gas and noise of the mower is already borderline unsustainable to me. Some of my neighbors spray chemicals, physically pull up weeds, or even drag giant barrels behind their mowers to smooth out the ground. And of course they remove any native plants the moment they pop up. Those activities are what I would consider unsustainable, because they require so much continuous input and provide so little output (just ask the pollinators who, thankfully, all flock to my house instead!).