Deathweed and Waterleaf support potion recipes and can be maintained in a home garden after you collect starter seeds.
PC / Global, current Desktop version
WHERE & HOW TO FARM
Where to farm
Deathweed grows on Corruption or Crimson grass; Waterleaf grows on Desert sand. Maintain both in Planter Boxes.
Find Deathweed in Corruption or Crimson grass and Waterleaf in Desert sand, then establish a garden with separate Planter Boxes. Deathweed blooms during a Blood Moon or full moon, while Waterleaf blooms in rain. Wait for the matching state when seed replenishment matters. Store herbs for potion recipes and retain seed stock for replanting. Planter Boxes keep future harvests accessible even though the original plants grow in different regions. Collect for a recipe and leave the rest of the garden intact.