Following late July surgery, an initial bout of boredom drove me outdoors in the worst of summer's heat.
While I would not for a moment describe it as invasive, or even aggressive, sporelings (baby ferns) of Japanese Painted fern (Athyrium niponicum var. 'Pictum', below) are common in the garden.
I suspect that each gardener has a particular weed that is most bothersome, and in this garden the most prolific is nutgrass (nut sedge, below).