Dear Ruth,
I recently moved to eastern TN from New Mexico/Colorado where many (organic) gardeners use capsaicin spray, powder, or oil from pepper plants (which you can buy easily there at most garden stores) as a good alternative to deter deer, rabbits, squirrels (and less effectively, gophers) from eating plants, and also as a general pest deterrent. I’ve spoken with a few people in the area but haven’t heard or seen it used in this region much. Do you have any more information regarding capsaicinoids and insect control?
Thanks,
Xanda Gordon
Dear Xanda,
Hot peppers (capsicum) are a New World plant originating from South America, probably in the region of southern Brazil to Bolivia. Some people can’t imagine enduring a meal without the spiciness of hot peppers. Hot pepper sauces like Tabasco® inspire legions of loyal followers, and hot pepper fanatics are always searching for the latest pepper with the hottest burn. Gardeners love the instant gratification of whipping up a fresh pepper salsa straight from the garden.
Despite the fact that many humans love hot peppers, capsaicnoids, the “heat” in peppers, is an irritant to mammals and insects. You could even say that (Michael Pollan style) as the hot pepper plant evolved, it favored its heat-producing qualities as a protection for its seed from mammals. Mammals tend to destroy the seed when they chew it, while hot pepper seeds can pass through a bird’s system and still germinate.
Peppers are rated by the Scoville Heat Index ~
- Sweet Bell Pepper: 0
- Tabasco® Sauce: 2,500 to 5,000
- Jalapeno: 2,500 to 9,000
- Cayenne: 30,000 to 50,000
- Scotch Bonnet: 100,000 to 350,000
- Bhut Jolokia “Ghost Pepper”: 800,000 to 1,041,000
- Common Pepper Spray (used for personal protection): 2,000,000 to 3,000,000
Hot pepper spray is considered a deterrent to insects and mammals, rather than an insecticide. As you can imagine when a rabbit or an insect touches/bites into a leaf/fruit covered with a hot pepper spray, their immediate reaction would be to spit it out and discontinue eating that plant. Hot pepper would certainly be irritating to the insect’s body. Using the Scoville Units indicated above ~ I would conclude that the hotter the pepper used, the more effective the spray is liable to be. However, Jalapeño peppers should be sufficiently hot to do the job without intimidating the preparer. And Xanda, keep in mind that Colorado and New Mexico have drier climates with lower rainfall and scant humidity ~ therefore hot pepper sprays would linger longer on the plants undiluted and demonstrate more effectiveness in dry regions.
Before delving any deeper into this topic, it should be stated that extreme caution should always be exercised when handling hot peppers (whether for use as food or as an deterrent to plant damage). Always wear rubber gloves when handling hot peppers. If you don’t wear gloves, the peppers will burn your hands. The seeds are the very hottest part of the plant. Be careful not to touch your eyes or any other mucous membranes when handling hot peppers. If you are blending the peppers, or cooking them on the stove, beware of the fumes in the air above the blender and in the steam above your pot. Speaking from experience, even something as relatively mild as Tabasco® will volatize in the steam and get in your eyes. When spraying your pepper mixture, don’t spray into the wind.
Local Farmer Feedback on using hot pepper spray:
I asked a few local farmers for their input on hot pepper sprays. A few had never used them at all, or responded like Vanessa Campbell of Full Sun Farm who said they “intuitively felt it didn’t work.”
Barry Rubenstein of B & L Organics said they don’t have rabbit problems, but that they had tried hot pepper spray to control flea beetles one season. They did not have good results, and someone suggested to him that he would have needed to spray almost daily to get good results.
Meredith McKissick of Sweet Earth Flower Farm (and OGS Director) had positive feedback: “I use hot pepper wax as a deterrent for leafhoppers. They are a vector for aster yellows, a common disease that can cripple crops of lettuce, dahlias and asters (among other things). Used in rotation with Pyganic [a pyrethrin spray] I have found it very effective at keeping my dahlias in great condition and weekly sprays to asters and strawflowers have helped as well…I have never used it on lettuce as I am not sure the effect it would have on harvest of the greens.”
Patryk Battle of Sparkling Earth Farm received a bottle of Hot Pepper Wax at a SAC conference years ago and still hasn’t tried it. Several times Pat has “used homemade habanero spray to keep rabbits off my newly emerging legumes. I blend a habanero in a bit of water till it is liquefied. I leave the lid on the blender for at least 15 minutes to be sure no habanero is breathed in by anyone. I strain it and then spray it with enough water to effect coverage. I usually use a surfactant or at least soap to make it last a bit. Although others who have tried this have reported mixed results, I have always stopped my rabbit problems first try. However I have always applied early ~ usually after the first sign of predation on my legumes.”
Reports on hot peppers as a deterrent are mixed. Rodale’s Chemical-free Yard & Garden states that “…Researchers have found that as little as 1/25 ounce of capsaicin [powder] sprinkled around an onion plant reduced the number of onion maggot eggs laid around the plant by 75%, compared to a control plant. Purdue University Extension’s Organic Vegetable Production researchers found that plant extract repellent products (such as hot pepper wax) “work poorly if at all, and we generally do not recommend them.” In a Cornell University test on broccoli transplants, Hot Pepper Wax was found to be as effective as Rotenone 5% on controlling flea beetles (this test was on transplants only and not a field test on larger plants). According to Clemson University, capsaicin can be used on ornamentals ~ outdoors and indoors ~ for control of aphids, spider mites, thrips, whitefly, lace bugs, leafhoppers, and other pests…they appear to be effective at repelling certain animal pests such as rabbits, deer and squirrels. University of Massachusetts-Amherst Extension points out that Hot Pepper Wax is no longer allowable for Certified Organic growers. The National Organic Program allows capsaicin, the active ingredient in Hot Pepper Wax; but does not allow the wax in current use.
(photo at left: Commercially Available Hot Pepper Preparation.)
Hot Pepper Sprays may target: rabbits, squirrels, deer, aphids, spider mites, whiteflies, cabbage loopers, beet armyworms, leafhoppers, and other soft-bodied insects that feed on the leaves, flowers, fruit and stems of plants. It seems to deter squirrels and rabbits better than deer.
Other Cautions: Some plants are extra-sensitive to pepper spray, such as basil, parsley, peppermint, African violets with variegated leaves, fruit trees in the pink-bud stage, and Bleeding Heart (Dicentra exemia). It is best to test your spray on a small area of plant material before applying to the entire crop. Hot pepper spray should be applied in the evening so it has all night to dry before the suns rays hit the plant in the morning. Spray the entire plant, paying special attention to the undersides of leaves. If you are using Hot Pepper Wax, the cool evening temperatures will allow the wax to harden on the plant overnight (and become transparent.) Remember that hot pepper spray will not protect new growth, and can also be harmful to beneficial insects. There is a zero hour re-entry after spraying hot pepper. Even though hot pepper wax washes off easily with warm water, some plants ~ like lettuce ~ may wilt when washed with warm water.
How often to spray: Reports differed substantially on this question ~ from repeat after rain, dew, or heavy humidity; to repeat every few days; to repeat in 7 to 10 days; to lasts up to 30 days. The wax product will probably last longest…up to 30 days. If you are making your own spray without wax, add dish soap or a surfactant to encourage the hot pepper to stick on the plant longer.
Homemade Hot Pepper Spray Recipe:
Remember to use rubber gloves and caution when handling hot peppers (see above).
- 5-10 Hot Peppers depending on size (from your garden or the market, or substitute powdered cayenne pepper)
- 1 teaspoon pure Soap (dish soap is OK, but not detergent types)
- 1 tablespoon of Vegetable Oil
- 6 or more cloves of Garlic (Optional)
- 1/2 gallon Water, or up to 1 gallon (use 2-3 cups in blender)
Put ingredients in the blender. Add 2-3 cups water. Blend thoroughly until liquefied, adding more water if necessary. Let stand one hour. Liquefy again. Let mixture sit until fumes have settled. Strain (through cheesecloth, coffee filter, paper towel). Dilute with additional water and spray on plants in the evening (using caution at all times when handling the material and during sprayer clean-up). Extra material can be stored in a jar in the refrigerator for a couple of weeks.
Xanda ~ welcome to the southern Appalachians and good luck with your gardening efforts in this area.
Best wishes,
Ruth
Ask Ruth © 2013 Ruth Gonzalez & Organic Growers School
Author: Ruth Gonzalez
Ruth Gonzalez is a former market farmer, gardener, and local food advocate who wants to see organic farms proliferate and organic gardens in every yard. She also served on the Organic Growers School Board of Directors. In her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the wisdom of local gardeners.
I was very excited when I read your story ,including the bug repellant recipe. I will try it this week. Do you have a cure for gophers? There are a lot out there but most do not get satisfactory results. Thank you for your helpful and informative articles.
For help with gopher control I highly recommend repeated viewings of the film “Caddyshack” paying close attention to the assistant greenskeeper, Carl.
Ruth, Do you feel, or have you experienced the effectiveness of a mosquito spray made eith cheap mouth wash, Epsom salt and stale beers? I just made some and sprayed. I live in GA and mosquitos are EVERYWHERE! If this is not effective do you have a concoction that is. I’m allergic to insecticides.
Hi Ronnie G.
I have not tried bug spray made with mouth wash, epsom salt or stale beer. But that’s an intriguing combination for sure.
What I try to do on my homestead as a first line is eliminate standing water. I go around the farm and the homestead and dump over anything that could be holding water like tarps, tires, plastic or metal containers, bird baths,e tc. Where I want standing water, such as rain barrels, I either employ mosquito fish or I use Mosquito Dunks, which you can buy at Lowes, HomeDepot or Amazon (https://www.amazon.com/Mosquito-Dunks-102-12-Killer-Pack/dp/B00LET25AE/ref=sr_1_3?s=lawn-garden&ie=UTF8&qid=1501542834&sr=1-3&keywords=mosquito+dunks). But don’t use both because Mosquito Dunks are harmful to fish.
After hunting for standing water, that helps eliminate lots of mosquitoes. From there I try to make my farm bat friendly. Between these two things, I get so few mosquitoes each year. Thankfully. Good luck.
Greetings, can i use hot pepper spray on roots in hydroponic garden? Will it kill the parasites & not harm the roots?
Thank you for your help.
Hey Syndi!
I’ve never heard of anyone using hot pepper spray in their hydroponics system, largely because the compounds that make pepper spray useful as an insecticide (capsaicnoids) are hydrophobic, meaning that they won’t mix well or distribute themselves in water. Also, capsaicnoids are mostly irritants to mammals, which I hope are not part of your pest issues in a hydroponics system!
The most common parasites in hydroponic operations are root aphids, which can be helped in a number of ways. Sterilizing your system and keeping it clean is very important, which you can do by regularly draining your system or treating it with super concentrated hydrogen peroxide. There is also an OMRI listed product called Azamaz that is useful for both root rot and root aphid problems.
Hope this helps!
Gophers are also known as woodchucks, groundhogs, whistlepigs, or as my 5 year old neighbor calls them BFG’s (big fat groundhogs).
Here’s why they are called whistlepigs: https://www.youtube.com/watch?v=hsnFsXFO7eY or https://www.youtube.com/watch?v=pCibiJrk4_Q.
You can poison them (slow painful death) or shoot them (quicker death) or trap them and kill them or trap them and remove them. Or get a really good farm dog or rat dog who will vigilantly go after them.
There’s not a super easy or quick solution for you. And unfortunately they will devastate your garden.
Homemade hot pepper spray works great against cucumber beetles. If you spray it in a dry summer and it does not rain, it will run them away in a day and they will generally not return. There are also many other bugs that are gringos. When spraying on fruit to keep squirrels away, it does work for a while. But, if the squirrels are without water in a summer drought, or extremely hungry, you can forget it. I have personally witnessed them destroy all my apples before in a drought when they most likely needed moisture in the apple. My apples were coated in homemade pepper/garlic/onion spray, and they stripped the tree anyway. The bitter herb is good to the hungry man, like an overly spicy apple is to a suffering squirrel.
You say it is OK to substitute cayenne pepper, but don’t say how much?
Having some issues with some form of mites on my skin, is there a pepper spray formula save to apply to your body? Thanks
I am also asking if powdered cayenne pepper would hurt the roots of veggie plants when included with the planting of an established plant in the ground. This is to help temporarily deter gophers and underground varmints. Yes I know it won’t last long with moisture but I have trapped 17 gophers ranging from 1/2+ pound to 3/4+ pounds and they are going strong. Took out 150 feet of ready to pick pole beans in less than a week. Should mention that peppermint, lavender & rosemary can help deter deer and coons. Unfortunately I seem to have every critter possible in abundance that can destroy plants, etc.
Help!!! We sprayed our tomato plants with the Tabasco sauce recipe. I think we have killed our plants. The leaves are turning brown and falling off. We have tomatoes on the plants. Anything we can do to help them??
Hello there!
I have the perfect image to go along this piece of content. It’s a comic-like walkthrough, showing the steps of making your own pepper spray for the garden.
If you want it I can send it to you in any format you want.
I am sorry Jim, but we don’t have any recommendations for human mites. I wish you the best health!
We will try to email you a response shortly
So sorry this happened! I would give them a watering, usually watering the leaves is frowned upon for fungal issues, but try to rinse off the solution. Sometimes if you treat plants with these methods during a hot sunny say, it can shock them too much and cause them to burn… Do it on an overcast cooler day for best results and make sure it is properly diluted.