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