Instructions
Play through the game until level six.
Buy a Ponocky from Gretchen and put it in your garden. Horstachios are attracted to Ponockys and will only visit your garden if you have a Ponocky and 500 pinometers of grass in your garden.
Feed the Horstachio eight apples. Feeding the Horstachio eight apples will change its status from visitor to resident and it will now become a permanent part of your garden.