There are 8 types of plants to grow in Hogwarts Legacy. Certain plants require small, medium and large pots to grow them. You won't be able to access the larger pots until you've completed the
main story quest "Room of Requirement" where you unlock your own room and can place bigger planting stations. The whole process
will cost you a grand total of 5,550 to acquire everything you need.
Once you've
unlocked the Room of Requirement. Buy the following
Spellcrafts from "Tomes and Scrolls" in Hogsmeade:
Potting Table With Medium Pot (750)
Potting Table With Large Pot (1,000)
Now conjure the Small, Medium and Large Potting tables into your Room of Requirement. Once placed we need to then source all 8 seeds to plant. These can be found at the two horticulture shops in Hogsmeade:
The Magic Neep:Dittany (Free) - Small Pot
Fluxweed Seed (350) - Large Pot
Knotgrass Seed (350) - Small Pot
Mallowsweet Seed (200) - Small Pot
Shrivelfig Seed (450) - Medium Pot
Dogweed & Deathcap:Chinese Chomping Cabbage Seed (600) - Medium Pot
Mandrake Seed (800) - Small Pot
Venomous Tentacula Seed (1,050) - Large Pot
Return to your Room of Requirement and plant the seeds in the appropriate pots. Small plants will take 10mins to grow, medium 12mins and large 15mins. Once you have collected all 8 from the pots at least once the achievement should pop.