Here is the full list of all 18 Strange Horticulture achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Perform the ritual
Complete a full playthrough without using the hint button
Take control of the Servant
Save the Sisterhood
Murder Burbidge
Identify all the plants
Complete the game
Bring about the Redemption
Create an Elixir
Find a Bryer's Disc location
Open the secret drawer
Activate the viewing device
Recover from Rising Dread
Visit 20 map locations
Identify 10 plants
Pet Hellebore 13 times
Solve your first clue card
Handle your first customer