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.
Bring about the Redemption
Take control of the Servant
Murder Burbidge
Complete a full playthrough without using the hint button
Save the Sisterhood
Pet Hellebore 13 times
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
Identify 10 plants
Recover from Rising Dread
Solve your first clue card
Handle your first customer