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