Here is the full list of all 18 Strange Horticulture achievements worth 1,000 gamerscore.
Handle your first customer
Solve your first clue card
It's a secret...
Commit a murder
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