Aka: weeds
A guardian plant (aka: weed) is a quick growing plant whose main purpose is to create ground cover as soon as possible to: retain moisture, keep the soil cool, generate shade for slower growing plants, provide floral arrangements until more well established plants grow, provide landmarks and homes for smaller creatures, keep soil in its place during downpours or flood, contribute to carbon matter that feeds larger plants.
Guardian plants are what most people call "weeds", but are actually very useful, and so the negative term needs refreshment.
Guardian plants are not enemies, they are valued members of the garden community.
Plant lives matter!
"Those guardian plants are not as pretty as my roses, but I know they will help the bushes grow stronger by providing them with shade."
"Some of those guardian plants have the cutest flowers on the tips, and the bees seem to love them!"
"I put one of the guardian plants in a pot by itself, it actually looks quite good!"
"Without those Guardian plants, the soil in my front yard wouldn't be as fruitful as it is today."