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