How about a new powder/potion/essence that makes it rain briefly, watering all plots/plants in the region at once? Animation like sparkle powder or fertilidust...
yes. people have asked for actions that do all your gardening for you at once. I can see that as an expansion of powders. Rain powder, Harvest powder, Hoe powder. (powders have gotten a little stale lately.) The trade-off is you don't get the same sort of mood / xp bumps you get from doing the plots individually, same as with fecundity powder.