There are no garden plants that repel snakes, but most snakes that hang out in a garden are harmless and can actually get rid of rodent pests. Let snakes live in a garden with plant advice from an urban horticulturist in this free video on gardening.
Are there any plants out there that'll help to prevent snakes from getting into your yard or garden, and the answer is no; not that I know of. Most plants, well they've been here forever, and so have snakes been. I will tell you, often people will come to me and they'll have a snake that they've just cut up into a hundred pieces and they put into let's say a mason jar. They'll ask me is it a good snake or a bad snake? And usually, my answer is it's a dead snake. In other words, most of our snakes out there are good guys. They're helping to take out rats and other critters in your yard and garden, so in general I'm going to say let's let everything live. You know, if you had a large rattlesnake or coral snake that might be a different story, but in general, most snakes aren't going to come after you. They aren't going to be aggressive. Watch where you walk, wear boots, wear shoes, wear long sleeve shirts and trousers when you're in a area that's wooded. But, in your own yard and backyard I wouldn't be too worried. There are really no plants that will help to prevent snakes in the yard or garden. There are some products that may help inside or around your home, and those will only last for a certain short period of time. For ask mrgreenthumb.com, I'm Stan DeFreitas.