Staff of Regrowth

Harvest a blooming herb while holding this and you come away with more of the plant and a much better haul of seeds than a pickaxe gives you. Across a full farm run that gap compounds into whole extra stacks, which is the difference between brewing potions freely and rationing them. If the herbs sit in a planter box, or in a Clay Pot, it also puts them straight back in the ground as you go, so a sweep of the farm is one pass instead of harvesting and then replanting the whole row by hand.

It flatly refuses to pick a herb that is not in bloom. That reads as a restriction and works as a safety net, since you cannot strip a farm early by running past it with the tool out. The cost is that you have to visit when the plants are actually blooming rather than whenever you happen to be home, which for Moonglow and Fireblossom means paying attention to the clock. Glowing mushrooms sit outside the system and give you nothing extra.

Swinging near plants leaves them standing. Flowers, weeds, vines, jungle spores, moss fuzz, cattails and lily pads all survive unless you aim directly at the tile they sit on. That makes it the thing to hold while walking through a jungle or your own garden, since almost anything else you might be carrying shreds ground cover on contact. It counts as a melee weapon on paper, which is a curiosity rather than an option. It hits for close to nothing.

• It turns bare dirt into grass with no seeds, anywhere, including the bottom of a cave. Underground that grass sits inert: it will not spread, weeds will not sprout on it, and planted acorns never grow up.
• It still works as a trail marker. A green stripe reads instantly against gray stone, so you can tag your route back out of a maze while you dig.
• Grow grass beside pearlstone, ebonstone or crimstone underground and it converts, which is a cheap way to seed a hallowed or evil patch exactly where you want one without hauling solution down.
• Sunflowers need only a pair of grassy blocks and some headroom, so lining an arena with them takes a few seconds of grass work.

Look in the Ivy Chests in the underground jungle, or fish up jungle and bramble crates. Later on it becomes the ingredient for the Axe of Regrowth, which keeps all of this behavior on a tool that also chops trees, and there is no reason to hold on to the staff once you have made one. On modifiers, harvesting only cares about swing speed, so Light is what you want for farm work. Legendary is only worth the coins if you have some strange plan to fight with it.