Green Thumb

The "Green Thumb" achievement, obtained after watering 100 plants to their final stage, is really something that demands time and dedication, but not only that, in case you don't have friends who have pots kept and stored, it becomes necessary to wait for the June flower event, and be able to obtain several flower pots with plants and thus be able to continue watering, through the exchange of seeds.

An alternative, perhaps not very well known, is to obtain a flower plant per day (or at each floor reset), which appears next to the NPC Onfroi de Bounac. This flower pot is already in the second stage (one above which you get by exchanging the seeds in June).

See the photo below: