Using Denatonium Benzoate Solutions to Repel Animals in Gardens.

Introduction: Using Denatonium Benzoate Solutions to Repel Animals in Gardens.

Lots of Animals can be very destructive to plants like Hostas and even toxic plants like Daffodils, etc. Especially Squirrels, Deer, and Groundhogs, etc. Besides Peper (Hot pepper spray) what can you use? Well, bitterex (Denatonium Benzoate at concentrations of 1 g per L or more) can be very effective since the animals only have to taste not bite into to get that very bitter taste. Most of the bitterex is spread carefully across the plant so the concentration is about 10 percent of that 1 g. So 100 mg per L of Bitterex. You're only using 10 ml so the entire crop has a very low concentration but for crops, I have sprayed animals like Squirrels have stayed away. Small amounts of coffee and Mint extract have been added to repel other animals like cats. Plus Cinnamon is used.


Step 1: How to Make the Spray.

Here the list of 1 L of chemicals needed.

1000 ml of tap water or distilled water.

1 g of Bitterex.

0.5 grams of Methanol

5 g of cinnamon

5 g of instant coffee.

You must make this stock solution and let it sit in a sealed bottle Labeled "Bitterex Spray". Store and shake every day for a week if you don't have acess to a distiller. Then filter with a filter (Make sure you don't use it again for food!!).

Dilute this by 1/5.

Note for the 0.5 g to 1 gram you will also need a scale. You can get a good one on E-bay tho.

Step 2: Sprayed Plants.

The plants were Spray with 20 ml each plant of bitterex and tested each day for 2 months. Bitterex is very long acting and even in trace amounts would be very unbearably-bitter to animals even in trace amounts. Once it absorbs into foliage and plants it very persistent in the plants for 2-3 months. So if it last 1 month (Half-life) in 3 months it would be 75 mg Bitterex per L (Still very strong--- strong enough to repel most animals from eating or even playing around your crops.).

Doses as low as 25 to 30 mg per L would be sufficient but I used 250 mg per L as a precaution measure (Weather, sunshine, other factors).

Sorry if the Pictures (Repeat).

Step 3: More Damaged Crops That I Have Sprayed With Bitterex to Deter Further Damage!!

Here are some pictures of what can happen within a few days by Squirrels. Bitterex is definitely used here to prevent them from digging up the soil and eating the plant. It being sprayed 30 ml for each Plant.

Note If you want more concentrated bitterex solution you may have to add up to 5.0 grams Bitterex per L then dilute it by 1/4.

Step 4: More Crop Sprays.

More Crops including Daffodils that were sprayed 3 months ago with bitterex which the squirrels chewed to the ground it has due to that chemical recovered fully. These chemicals are proven to work since in several weeks later no animals like Groundhogs or squirrels have touched the back hostas.

This is proof that bitterex can work as a repellant for animals.

Most of the young hostas (Not shown) have been sprayed with Bitterex at a young stage. It has been several months and nothing has eaten them (Mice, Groundhogs, Squirrels, etc). A good alternative for insects too. It also affects some insects too.

Here is a before of a Tulip eaten by Squirrels. Bitterex spray B has been sprayed on plants. I also sprayed Bitterex A on other plants and found no difference in repelling animals. However, Menthol and Cinamon in spray B besides coffee (1 teaspoon of Instant) repelled by info animals like cats too.

However their are Limitation with Bitterex in both forms so for Mice and Rats that could be eating crops article 3 (References) indicates mixed reviews about Bitterex and Rat poison use. This means if Bitterex was going to be used for mice and rats that eat crops it may fail.

Also, Bitterex must be at least 1.0 grams per L. So apply it doubly or add 2.0 g of bitterex per L for 25 ml of Spray. Below 1 ppm for animals becomes ineffective at repelling them. That my final word for now. It does work well for Hostas that were damaged (Not shown) and recovered after 1-2 months that would have died without the spray. Keep that in mind.

Step 5: Some References.

Be the First to Share


    • Pocket-Sized Speed Challenge

      Pocket-Sized Speed Challenge
    • Metalworking Contest

      Metalworking Contest
    • Maps Challenge

      Maps Challenge



    1 year ago

    Keep in mind you must apply this dry on plants 24 hrs before a rainstorm that an Important part of making it work correctly. If wet it quickly washes off the plant but if left on 24 hrs to dry it is trapped into the plant and can last 4 months or so.