How can I repel snakes organically?
Get rid of their food source. Snakes are part of a healthy eco-system, they eat rodents, bugs, etc.
Get rid of food sources of course and put Osage orange tree fruit aka "hedge apples" by entrances of crawl spaces, entrances, etc. this an old pioneer method probably learned from the natives. There is also a chemical property to this fruit that supports this. It works for spiders too if you get rid of eggs and webs first. You also get rid of a snakes' food source.