In my last post, I wrote about how deer repellents are classified. In this post, I want to highlight the products that researchers have noted for being the best deer repellents. But before I explain which products were the best deer repellents, I want to give you the bad news. No deer repellent stops damage by deer 100% of the time. If your goal is to have a deer repellent stop deer browse completely, then you must understand that no repellent has done that. You may counter that the product you used did stop deer damage. That may be true, but why it is true is more likely a function of low deer density and the availability of alternative food sources for the deer. The fact is, if deer are hungry they will eat regardless of whether the plant has been treated with a repellent or not.
Best Deer Repellents
When looking at deer repellent ignore the fancy marketing names and images. Focus instead on the small print which contains the active ingredient information. Active ingredients are the key to effective chemicals. Plus you will see how lots of products with different names have the same active ingredients. Don’t be fooled.
- Ammonium Soaps of Higher Fatty Acids: This active ingredient causes nausea in deer that eat treated plants. Research showed that this chemical could reduce deer browse damage by 50%.
- Capsaicin: Capsaicin is what makes chili peppers hot. When applied to plants it repels deer through pain. Concentrations at 6.2% repelled deer for up to 2 weeks. But concentrations at 0.062% had no effect on deer. Do you recall me saying that you needed to read the label?
- Coyote Urine: Predator urines repel deer by evoking fear. Some efficacy has been demonstrated with coyote urine but it wasn’t impressive. Keep in mind that you should only be using products registered by the Environmental Protection Agency AND your state’s pesticide regulating agency.
- Dried Blood (Bovine or Porcine): Plantskydd is the product that uses dried animal blood. Researchers found it can repel deer for up to 11 weeks in the winter but only one week in the spring. Other tests found that the efficacy of the product was even lower.
- Thiram: This is a fungicide that was found to repel deer by changing the plants’ taste.
- Putrescent Whole Eggs: This is another fear-based repellent. Products with this active ingredient had the highest efficacy on average over all the deer repellent studies. So you could say that it is the best deer repellents.
Bottom Line
Follow labels carefully. Keep track on how well the products work or don’t work. Don’t be afraid to try a different active ingredient because it may work better than what the researchers found in your situation. Understand that what works in the winter may not work in the spring and vice versa. Have reasonable expectations.
Stephen M. Vantassel, CWCP, ACE, is the owner of Wildlife Control Consultant, LLC. He helps people restore their balance with nature through publishing, training, consulting, and the internet. He has published numerous articles in trade and academic publications available at {Stephen’s Academia.edu Page} along with several books {WCC Store}). Listen to his podcast “Living the Wild Life” at {Pest Geek Podcast}. Please subscribe to {Stephen’s YouTube Channel} He is a sought after speaker and trainer. If you would like to have Stephen speak at your event or use his consultation services, send an e-mail to wildlifecontrolconsultant@gmail.com. Copyright All postings are the property of Stephen M. Vantassel and Wildlife Control Consultant, LLC. Text (not images) may be reprinted in non-profit publications provided that the author and website URL is included. If images wish to be used, explicit and written permission must be obtained from Wildlife Control Consultant, LLC.