Castor Oil For Garden Use: Tips On Treating Pests With Castor Oil

Castor Oil For Garden Use: Tips On Treating Pests With Castor Oil

By: Bonnie L. Grant, Certified Urban Agriculturist

Trying to be a good steward to the earth means minimizing your impact on the natural order of life. We do this in many ways, from driving a low emission car to choosing local foods at our supermarket. Another way to limit our negative influence on the earth is by gardening smart: use safe, non-toxic herbicides, sustainable gardening practices and natural pesticides. Using castor oil in the garden can be part of good garden management without the potential side effects that commercial formulas may cause. Read on to learn more.

What is Castor Oil?

For many of us older gardeners, castor oil represents a childhood trial. Once upon a time, mothers gave their children castor oil to regulate digestive health. It was once thought to be good for the digestive system and spoonfuls of the foul stuff were force fed into unwilling children’s mouths. This foul tasting practice has gone out of fashion in favor of other better tasting and more convenient over the counter remedies, but that doesn’t mean we need to retire the oil. There are many beneficial uses for castor oil, such as using the oil as a pesticide.

Castor oil for garden use may repel voles, moles and possibly other digging and tunneling animals, such as armadillos. Treating pests with castor oil is a natural, non-toxic way to repel these unwanted digging animals in your garden without hurting them or causing poisonous chemicals to build up in the garden and ground water. Additionally, using castor oil as pest control is non-toxic and safe around children and pets.

So where does castor oil come from? The castor bean plant, which is occasionally grown in gardens as an ornamental – BUT its beans are toxic and shouldn’t be grown where pets or small children are found. The oil itself, however, is safe and readily available through most retailers.

Castor Oil for Garden Use

Wild animals can pose a problem in the home garden. Mole hills pop up overnight, skunks dig up prized plants in search of grubs, and squirrels unearth your bulbs and render them useless for the bloom season. One way to minimize the damage that naturally occurs when animals forage is to use castor oil as pest control.

It may sound silly but this out of fashion medicinal is a common part of natural commercial pesticides. How does castor oil repel animal pests? It seems the bitter taste and the unpleasant smell are the key. Just as children had to hold their noses to take the stuff back in the day, so too, our animal friends are sickened by the ripe odor and bitter taste.

Using Castor Oil in the Garden as a Pesticide

Castor oil won’t kill animal pests, but it will repel them. To harness the effect, you need to apply castor oil directly to the soil. The formula will work for a week or so even in the rainy season. Weekly applications are the most effective at controlling animal damage in the garden.

Use a hose end attachment and spray a mixture of 2 parts castor oil and 1 part dish soap. Mix the two items until they are foamy. This is the concentrated solution and needs to be used at a rate of 2 tablespoons (29.5 ml.) per gallon (3.7 l.) of water. Apply evenly to the affected areas.

Treating pests with castor oil weekly will see fewer mole hills and dug up garden beds without any danger to your pets and children or the environment.

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Castor oil is a slightly thick, oily liquid that is pale yellow in color. Although it has only a faint odor, many people find that it tastes disgusting. It is composed of several different glycerides, the main one being ricinolein, or glyceride of ricinoleic acid. It does not combine well with water, so when mixing you’ll have to shake it. Beware that it is combustible, so store it safely. Castor oil’s supposed effectiveness is based on the fact that moles find the smell irritating and will try to relocate away from it.

Unlike many types of repellent, you will use castor oil not on plants but in soil, since it aims to keep moles from entering your garden at all. Commercial repellents use concentrated pellets or liquids composed of castor oil and other irritating ingredients to drive moles away. You may also try a mixture of 6 ounces castor oil in 2 gallons of water with 2 tablespoons of detergent. Use a sixth of this mixture for 1,000 square feet of soil, spraying before a rain or watering afterward so it will soak in.

Ways To Control and Prevent Armadillos

You can follow the solutions listed below to control and prevent armadillos in your garden, flower bed, or lawn.

Spray Homemade Armadillos Repellent

Spray the repellent in your garden as well as flowerbeds every month. Also, look for burrows and holes around your lawn and sprinkle repellent in them.

Use Traps

Using a trap is an effective way to control the armadillos. Set traps in the burrow’s entrance and fences to capture the little armored ones. Later, release them in a remote place.

Try Red Pepper Flakes

Crush red pepper flakes and sprinkle them in the flower bed, yard or garden. The strong and pungent smell of the red pepper flakes will keep the armadillos away.

Buy an Electric Repellent

Get an electronic repellent online or from a nearby general store. It’s motion-controlled and sprinkles water to repel the armadillos. You can place it near plants, vegetable gardens, flowerbeds, and pathways, where these tiny mammals may travel.

Make Ammonia and Murphy Oil Solution

Combine one part of murphy oil soap and four parts of ammonia in water. Spray it in the areas prone to armadillos regularly. Always mask and goggles while spraying it!

MolEvict Lawn Mole Castor Oil, 1 Gallon

MolEvict ® Lawn Mole Castor Oil, 1 Gallon
Covers up to 20,000 sq. ft. (About Half an Acre)

There are many, many different types of castor oil. There is a type of castor oil for soaps, another for sealants, another you may have taken internally, another for pharmaceuticals, skin care, just to name a few. These types of castor oil will not work. We offer a particular type of castor oil that is specifically repulsive to lawn moles. Something in our oil's scent, texture and composition makes these unwelcome critters want to vacate your premises as fast as they can, and that's good news for you. Added bonus: Our customers report that our castor oil is also effective in chasing voles and gophers. They are trying our castor oil on armadillos as well!

Moles' appetites can be voracious, and they will often eat more than their weight in food every day. When searching for food, moles are very active tunnelers, often moving at a rate of 12-15 feet per hour. These burrows can damage lawns and gardens. While moles seldom feed on plant materials, mice may follow mole burrows, damaging bulbs and plant roots.

How MolEvict Works

Our special Baar Castor Oil, MolEvict ® , will drive pests away. For best results, apply every few weeks. A growing number of homeowners are finding castor oil an effective way to get rid of moles, voles, gophers and more.

How Much Should I Use?

How much to use can vary. Do you have clay soil or sandy soil? Everyone's property is different. The application process can be an art. But here's what we suggest to start. You can vary the amount and number of times applied depending on your soil. When using a garden hose and sprayer, the Gallon size covers up to 20,000 sq. ft. One Quart covers up to 5,000 sq. ft. Best to buy a sufficient supply for re-application. MolEvict should be applied 2 times per month, then apply as needed for maintenance. The 5 Gallon size covers up to 100,000 square feet!

Customers' Experiences:

"MolEvict works great to eliminate voles from our mulched flower beds." - M.B., York, PA

"We have used MolEvict from you folks before and it works great. We ran out last year, so I am ordering again. Moles don't like it at all!" - D.T., Albany, NY

“After much research, we decided to buy MolEvict to treat our mole and vole infestation. We're now three days into treatment and are AMAZED at how well this product works. We can literally see trails opening up as the moles/voles move out of our yard. Can't say enough good things about this, as the voles were destroying our grass and bushes - hopefully we caught them in time before they ate our tree roots too! Thanks to Baar for making such an effective and pet friendly product - and thanks to previous reviewers who helped persuade us to try it. The moles and voles aren't too happy about our purchase - but we're delighted! 5.0 out of 5 stars” - C.G., Canton, OH

"I've used MolEvict and it worked. I haven't had it for a while now and the moles are taking over!" - C.S., Chattaroy, WA

"Thanks! MolEvict really does seem to deter voles, and has not harmed any of my plants." - S.T., Black Mountains, NC

"I am repurchasing MolEvict. It is more effective than the bags of mole product offered by garden supply companies." - S.W., Lubbock, TX

"This is my second order of the MolEvict. Although I am using it for Vole control, I wanted to let you know I followed directions and sprayed twice (with a hose attachment sprayer). After the first time their activity was much reduced, and since the 2nd application, I see no evidence [of the Voles]. I have been chasing the critters for 10 years, using everything under the sun, with no success, but the MolEvict has chased them away. I want a back-up bottle to be ready for spring. Thanks." – A.M., Charlotte, NC

"I have been fighting moles and voles for years in my garden. The tunnels have allowed voles to eat a lot of young corn plants and seed. I started by spraying the aisles. That was enough for the moles. Now I just do a maintenance spraying before it rains and the moles have been very slow to return. Wish I had tried this years ago. Probably would have reduced the number of gray hairs I have." - S.C., Abbeville, SC

“After much research, we decided to buy MolEvict to treat our mole and vole infestation. We're now three days into treatment and are AMAZED at how well this product works. We can literally see trails opening up as the moles/voles move out of our yard. Can't say enough good things about this, as the voles were destroying our grass and bushes- hopefully we caught them in time before they ate our tree roots too! Thanks to Baar for making such an effective and pet friendly product - and thanks to previous reviewers who helped persuade us to try it. The moles and voles aren't too happy about our purchase- but we're delighted! 5.0 out of 5 stars” - C.G., Canton, Ohio

". It is not the sort of product that can be applied once and expect it to last throughout a summer season. I have had a severe mole, vole, and ground squirrel problem for the past 20+ years and have tried all sorts of solutions, i.e., poison worms and grubs, all sorts of traps, electronic vibrators and poison pellets. Some of the in-ground traps have been moderately successful, but the problem still continued year after year. This year I applied MolEvict on a monthly basis. At first the moles went crazy and torn up my property much more than they normally do, but after a couple of weeks they left the area. Since I have started the monthly treatments they have not returned except for one who I caught with an in-tunnel trap. My property is the best it has been in the past 20 years with the monthly treatments. Do not expect instant results. It takes a little time to train the moles to avoid your property. 5.0 out of 5 stars.” - S.F., Midwest

"I bought three gallons of your MolEvict last fall but didn't apply it until this past Spring. . Well, it worked very well! Within a couple days the moles were out of the lawn and keeping my cat busier than ever. There were no negative effects whatsoever. I mixed it in a tank sprayer and applied it using my lawn tractor. The detergent emulsified the oil and it applied very evenly. The results were evident within a couple days. Due to the amount of rain we've had this year I find I must re-apply. That's why I'm ordering the 5 gallon bucket. Thanks! Great stuff!" - M.P., Northfield, NH

"I followed your instructions about dish washing detergent mixed in with MolEvict. That worked well. But I heard about adding Red Cayenne Pepper to the mix. I did yesterday. About ten minutes after I sprayed, my cat went running to the area I had sprayed and grabbed a mole that had actually came out into the sunlight to get away from the mixture. Within an hour I witnessed a total of three moles surface. It was amazing. I guarantee they will think twice about returning, at least I hope they are smart enough. I used about 2 table spoons of pepper, just enough to turn it Pinkish Orange." - S.B., Hendersonville, NC

"I used MolEvict for moles a year ago and they are just now trying to come back. It does a great job of keeping them away." - S.S., Boyce, VA

"I am so glad this stuff [MolEvict ® ] exists and it does work where nothing else will!! Thanks!" - S.S.

". I tested your oil on my yard and after a week out of a dozen mole runs there are zero runs with new activity. I mixed your oil with natural orange cleaner to create an emulsion and filled milk jugs with the mix and water and shot it around the yard and I am really surprised by the rapid and complete success. Have ordered a gallon. Thanks and be well." - D.S., Oakland, OR

"I can't believe how well this stuff works! Thanks!" - D.J., Tehachapi, CA

“Great deal on a gallon of mole repellant. 5 out of 5 stars.” - R.T., Carbondale, IL

Active Ingredient: Castor Oil, 100%.

Other Ingredients: None.

Caution: Since product can cause mild irritation, the use of safety glasses is recommended. In case of eye contact, rinse with fresh water for 5 minutes. If irritation persists, seek medical attention. Keep out of reach of children. Store only in original container, in a dry place inaccessible to pets and children. Do not contaminat food, feed or water by storage or disposal.

Directions for Natural Mole and Vole repellent

Follow the directions in the “How To” card at the bottom of the post for the mole repellent recipe. Spray the mixture all over your lawn and pour it directly onto the mole hills.

Watch the video for the full instructions:

Here’s why natural mole repellent with Dawn and castor oil works:

Moles hate castor oil. When you apply it to the soil, it acts as a natural repellent. The castor oil doesn’t kill the moles but it will upset their digestive tract and cause stomach upset. If it get on their skin, it will make them itch. The castor oil won’t cause permanent damage but it will make them reroute their tunnels elsewhere.

Mixture of Dawn, castor oil and water to make mole and vole repellent

How to Get Rid of Moles in Your Yard

Natural Mole Bait

Using this natural mole repellent will change the way the insects taste in your yard. With your own mole repellent, the active ingredient is castor oil, which is responsible for changing the way insects taste.

Recipe for Homemade Mole Repellent

  • ¼ cup castor oil
  • 1 tablespoon cayenne pepper
  • 2 tablespoons liquid dish detergent
  • 6 tablespoons water

Add castor oil, cayenne pepper, and liquid dishwashing detergent to a blend. Mix on high speed until thoroughly blended. Add water and blend again until mixed properly. Pour the solution into a sealed container. Store the mixture in a cool, dry location.

As you see new mounds, add two tablespoons of the solution to one gallon of water and mix well. Pour directly into mole holes. The solution needs to be sprayed or poured around each mound of dirt and along the tunnels.

Homemade Mole Trap

A homemade mole trap allows you to trap and kill any pest you capture. This easy trap requires two shovels and a bucket. As soon as you spot a mole making a tunnel, you need to follow it with a shovel.

Stick the shovel in the dirt in front of the mole to block off the tunnel. Wait until the mole reaches the first shovel and then stick your second shovel into the ground directly behind where you think the mole is.

Place a bucket in between the two shovels. Wait for the mole to dig up and out and then scoop the pest up inside the bucket.

Castor Oil Mole Repellent

One of the benefits of castor oil to take care of the problem is moles do not like the oily or slick feel of the solution. If the first application doesn’t work, you will need to add more of the concentrate to the gallon of water and reapply.

Soap, Oil, and Water Mole Repellent Recipe

Add castor oil and dish soap into a jar with a lid. Close the jar and shake well to mix contents. Mix several tablespoons with a gallon of water. Pour solution directly into molehills.

Reapply after rain or as needed for new mole activity. This solution may also help as a homemade grub worm killer.

How to Get Rid of Moles with Fencing

Meadow voles, moles, and other burrowing pests want the most accessible path to their meal. Installing a mole-proof fence underground will block their way and make finding their favorite food source difficult.

If you need an effective method to deter lawn pests in your garden use ¼ inch hardware cloth to create the mole fence, cut the hardware cloth into pieces that are 20 inches high and as wide as needed to protect specific areas.

Use snips or wire cutters to cut the hardware cloth. Each piece needs to bend at a 90-degree angle, so the sides are 10 inches long. One side of the hardware cloth needs to lie flat against the ground, so the mower doesn’t catch it. Bury the other side along the perimeter.

Compost as a Natural Repellent

Moles love to munch on white grubs, worms, Japanese Beetle Grubs, and many other insects they are not after your garden plants. If you start a compost pile several feet away from your planting areas, you will be able to draw the pests away by providing them with another food source.

Milky Spore Pest Control

One way to eliminate a mole infestation is to remove its food supply. Grub worms are a favorite food source for many burrowing pests, so you want to start eliminating them in early spring. Milky spore, when applied regularly to large areas, will result in the elimination of grub worms.

As naturally occurring bacteria, milky spore as a grub killer provides a long-term solution as it survives freezing temperatures. Milky spore’s population will increase each year and reach peak effectiveness after three years of the initial application.

Homemade Mole Killer with Chewing Gum

Chop up several packs of chewing gum into fingernail size squares or smaller. Find the freshest mole tunnels you can locate close to the surface. Carefully dig into the tunnels.

You only need a large enough hole to allow you to drop several squares of gum into the pit. Dig several holes a few feet apart from each other and place gum into each hole. Be careful not to collapse the tunnels.

Reapply the chewing gum once a week for several weeks. If after two months you still have moles, there are several other common home remedies you can try.

Kitty Litter

Urine soiled kitty litter is a natural way to rid your lawn of moles. Pour 1 cup of used kitty litter into each molehill you see in the problem areas. Used kitty litter can also be poured directly into mole tunnels.

Cover the kitty litter with dirt from the tunnel or mound. The urine odor suggests predators are around so that the pests will leave for somewhere safer.

Garden Hose for Mole Control

This do-it-yourself pest control method is not the best way to solve your pest problem, but it can work as a temporary solution. Flooding the burrows causes them to flee to other areas, including your neighbor’s yard.

Stick a garden hose into the hole directly. Turn on the water and let the water fill the burrow. For larger areas, you may need to insert the hose in numerous locations.

Allow the water to run for 30 to 60 minutes. The flooding will either drown these garden pests or cause them to flee to nearby areas.


We want to thank you for reading through these natural mole repellent tips and recipes. If you have found any of these common home remedies helpful, please take a minute to share our article on Facebook and Pinterest.

One often-cited study, "The Effectiveness of a New Mole Repellent for Preventing Damage to Lawns by Eastern Moles," was conducted by Michigan State University researchers in 1993/1994. It showed that a liquid mole-control repellent containing castor oil did have some effect on reducing active mole tunnels. But there is no research showing that the use of castor bean plants themselves as a "living fence" against moles is effective. In a paper on "The Control of Vertebrate Pests in Renaissance Agriculture," Karl Dannenfeldt, a professor of history at the University of Arizona, cites a field experiment from the 16th century that showed castor bean plants didn't work for repelling moles.

  • Ricinus communis extrudes an irritating sap, which contains ricin, an effective insecticide, according to "Rodale's Illustrated Encyclopedia of Herbs."
  • In a paper on "The Control of Vertebrate Pests in Renaissance Agriculture," Karl Dannenfeldt, a professor of history at the University of Arizona, cites a field experiment from the 16th century that showed castor bean plants didn't work for repelling moles.

Watch the video: How To Harvest Castor Beans Seeds - Organic Pesticide, Organic Fertilizer available in Zimbabwe