Deer repellents are basically anything that deer don’t like to smell or taste. One of the best tips in this short video on deer repellents is that deer get used to any repellent - so change your products from time to time. Also, deer repellents wear off so you need to reapply, especially after a rain. Or you could do what I do and forget about deer repellents and just concentrate on planting things that the deer don’t eat or can’t reach!