Here is the full list of all 33 Garden Simulator achievements.
Throw trash into the garbage container from a significant distance.
Walk on the roof.
Give your cat some water.
Play for one whole week.
Mow half a square kilometer.
Own 50 garden coins.
Own 250 garden coins.
Own 500 garden coins.
Throw trash onto the roof and make sure it stays there.
Throw 10 garbage objects out of your garden.
Don't water a field of 6 strawberries for 3 consecutive days.
Spend a whole day without touching the ground.
Own 20 garden gnomes.
Own the most expensive gnome.
Hit a bird.
Harvest 20 plants by mowing them with the push mower in one go.
Pet your cat.
Don't go to sleep in the evening for quite some time.
Rescue trash which flew outside of the garden.
Make a pile of 20 trash objects.
Cultivate a field of 25 fully-grown plants of the same type.
Own 1000 garden coins.
Own 2500 garden coins.
Own 5000 garden coins.
Own 10000 garden coins.
Own 100000 garden coins.
Cultivate a field of 10 fully-grown strawberries and melons.
Cultivate a field of 40 fully-grown corn.
Grow one of each flower in your garden.
Cultivate a field of 40 fully-grown tulips.
Cultivate a field of 100 fully-grown chillies.
Unlock a garden extension.
Unlock all garden extensions.