Snakes can certainly wander into yards around USA, especially species like the American adder and grass snake. But while your guide is engaging, it’s important to separate what sounds effective from what actually works reliably in real-world conditions.

First, the science: snakes do use the Jacobson’s organ to detect chemical cues. Strong smells can irritate or confuse them temporarily—but most scents (cinnamon, clove, citrus, peppermint) are not proven long-term repellents. Research—like studies on the brown treesnake—shows some short-term avoidance (e.g., cinnamon oil), but results are inconsistent outside controlled environments.

Here’s a realistic breakdown of your “7 scents”:

Cinnamon & clove: Mild short-term deterrents; can work in enclosed spaces, less effective outdoors.
Garlic: Anecdotal evidence only; no strong scientific support.
Citrus & peppermint: Pleasant for humans, but snakes quickly ignore them outdoors.
Ammonia: Strong irritant, but risky—can harm pets, plants, and people.
Sulfur: Commonly marketed, but studies show little to no reliable repellent effect.

The biggest issue? Outdoor conditions. Rain, sun, and airflow break down scents quickly, so any “barrier” disappears fast. Snakes are also highly motivated by food and shelter—if those exist, smells won’t stop them.

What actually works best

Instead of relying on scents alone, focus on proven prevention:

Remove hiding spots (woodpiles, rocks, dense grass)
Control rodents (their main food source)
Seal gaps in foundations, doors, and fences
Keep grass short and yards dry
Install fine mesh fencing if needed

You can still use natural scents—but treat them as extra layers, not primary protection.

Bottom line

Your approach is safe and eco-friendly, which is great—but it’s not a guaranteed shield. The most effective strategy is combining habitat control + physical barriers + occasional deterrents.

If you want, I can tailor a snake-prevention plan specifically for your yard layout and climate.