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.
Take control of the Servant
Bring about the Redemption
Murder Burbidge
Recover from Rising Dread
Identify all the plants
Complete the game
Complete a full playthrough without using the hint button
Perform the ritual
Save the Sisterhood
Create an Elixir
Open the secret drawer
Pet Hellebore 13 times
Activate the viewing device
Find a Bryer's Disc location
Visit 20 map locations
Identify 10 plants
Solve your first clue card
Handle your first customer