How do I keep snakes out my yard?

Unless they are poisonous, they're good to have around as they eat mice and other critters. If you don't want them in your yard, make sure there are no critters they can eat. If you take away the food source, (including bird feeders as some eat birds) they will move on.

There is very little you can do except make the area not as snake friendly. Some dogs like Jack Russells will take care of them for you. Get rid of debris and other hiding areas. Moist damp areas. Beds with rock beds help. Fill cracks and holes in foundation. If you have ponds good luck. Too many food sources near them.

Why would you want to? I agree with the others. If you don't want snakes taking up residence in your yard, then get rid of the mice, the big hairy spiders, the cockroaches, and the rest of the nasties. Good luck with that.

Unless you have venomous snakes, think twice. They eat bugs and rodents. If you do have poisonous snakes, you can install snake fencing.

http://www.snake-removal.com/fencing.html

If you don't provide habitat and food sources, then they will avoid your yard. Remove all ground litter, rocks, trash, boards they can hide under. Then put out mice traps to remove their favorite food source. Fill all cracks and holes in your foundation. Put a foot of rough gravel around the house and keep shrubs etc trimmed away from house.

If your terrified of snakes, add a snake fence of 18" of hardware cloth around the yard. You can also plant a perimeter of snake repelling plants around the yard perimeter.....https://www.pests.org/best-plants-that-naturally-repel-snakes/