Snakes do not like flea and tick yard granules, even if sprinkled in a garage, as my mother did in her garage. Of course, a lot depends on what other animals and children you might have on site.
There is a product out called I must garden snack repellent all natural won’t harm animals or humans
I put ONE by each door, ONE on each side of the porch. I specify ONE because they will have a strong odor to the snakes, not so much for humans. When the ball melts, replace it. Just don't let pets (My dogs HATE the smell) or children get hold of them!
They ARE toxic, that's why I said to keep away from pets and children. I disagree with them NOT repelling snakes. We had a LOT of copperheads, for several years, in our yard, where my grand kids play. After placing these at door entrances and our porch, we have not had them near our house. They can have the acreage, I want my yard.
If you have snakes, you have a food supply for them, i.e. rats and mice. Snakes are actually beneficial in the yard. If poisonous (I deal with rattle snakes almost every day), then that is a different story. Here are some things you can try.
You might also consider snake fencing.
Be careful with purchased or home remedies if you have pets or children. Many can be toxic to them.