Shiverthorn Seeds

This is the one herb with no timing attached to it. Once a plant finishes growing it stays in bloom for good, so there is no window to catch and no harvest wasted on a plant you cut a minute too early. Put in a row, walk off, come back whenever you like, and everything you cut hands seeds back. Set that against the herbs that only open at night, only in rain, or on a coin flip.

Snow and every kind of ice will take them, and so will clay pots and planter boxes, which means the row can live indoors next to the rest of your alchemy setup. They do not need the snow biome itself, only the block underneath. They will also sit happily submerged in water or honey, which is worth knowing if you are stacking farm rows into a tight space.