Be part of a Connecticut study on home-recipe deer deterrents…
One of the most frustrating aspects of gardening is to have your lovely plants and shrubs and your hard work and hard-earned cash disappear overnight into the belly of one of the estimated 80,000 deer living in Connecticut. This is even more frustrating after spending additional ‘green’ on commercial products purported to deter deer browsing.
Scientists at the Connecticut Agricultural Experiment Station (CAES), in New Haven, and others have done quite a bit of research on commercial deer repellents (more on this below). Now researchers at CAES are extending their investigations to homemade formulations and they want to hear from you.
Here’s their request:
The Connecticut Agricultural Experiment Station is continuing its research into the effectiveness of repellents to prohibit deer browsing on agricultural crops and homeowners’ landscape plantings and gardens in Connecticut.
Do you have a home-brewed deer repellent you think works well?
We are soliciting unique, effective “home remedy” deer repellents to evaluate alongside commercially available repellents. If your home remedy is selected and you are willing to assist us, we will recreate your home made deer repellent solution and treat test plants in our research plots. We then will evaluate and rate the effectiveness of each of the treatments.
Please follow this link HomeBrewedDeerRepellents to a solicitation survey form. Please fill out the survey as completely as possible, make sure to describe the remedy you use in full detail.
Please feel free to e-mail me with any comments or questions.
Agricultural Research Technician
Dept. of Forestry & Horticulture
The Connecticut Agricultural Experiment Station
The study will run through 2011 and possibly through 2012, but to make the study work CAES researchers need homemade recipes. Over the winter of 2001-2012 they plan to report the findings from the 2011 growing season. If they are able to extend this study into 2012 they will report two-season results over the following winter.
CAES scientists already have data on the efficacy of commercial deer repellents. [Reference: Ward JS, Williams SC, Effectiveness of deer repellents in Connecticut, Human-Wildlife Interactions 4(1), Spring 2010] They evaluated how 10 different types prevented deer from browsing deer-fave yews (Taxus cuspidata) over two growing seasons. The egg-based products – Deer-Away Big Game Repellent, Bobbex, Liquid Fence – were generally most effective. They found Hinder, made of ammonium soaps of fatty acids, and Thiram-based (tetramethylthiuram disulfide) Chew-Not which is no longer available, nearly as effective as the egg-based formulations. Their findings show Deer Solution, , Repellex systemic tablets, Plantskydd, and coyote urine least effective.
Research from Cornell University in Ithaca, New York also found egg-based solutions most effective among the repellents they tested on yews over 10-weeks. [Reference: Curtis PD, Boulanger JR, Relative Effectiveness of Repellents for Preventing Deer Damage to Japanese Yews, HortTechnology 20(4), August 2010]
This does not mean that egg-based repellents work for all plants and on all deer. Only a properly constructed, designed, and maintained physical fence can provide real protection. For a small garden, such as a vegetable plot, a 5’ or 6’ tall fence should suffice. Deer need running room to leap over fences so minimizing this helps to keep them out of small enclosed spaces. Large areas – think an expansive yard or garden – need fencing 8’ to 10’ tall to keep deer out. Also, any fencing needs to be hole-free for obvious reasons and secure enough at the lower edges to keep deer from sneaking in under the fence.
Homeowners can also spring for deer-tolerant plants. Follow this link for a University of Connecticut Home and Garden fact sheet – scroll down to and click on “Deer and Plants They May or May Not Eat, Maybe!” or check out the books, Deer Proofing Your Yard & Garden by Rhonda Massingham Hart and Gardening in Deer Country by Vincent Drzewucki, Jr. All these sources provide good background information on plants deer may not eat but the best information on deer-tolerant plants will likely come from local garden experts and your own trial and error.
Different deer have different tastes. I’m “blessed” to have deer neighbors that nibble on one type of early narcissus, a supposedly deer-tolerant bulb. I’ve also found a fish-based spray to deter deer browsing in my gardens while the proprietor of a local garden center has had the opposite experience.
This leads back to the importance of knowing which repellents work best and which don’t work at all … so help out with the CAES study. Fill out the HomeBrewedDeerRepellents survey and check back here next winter for any reported results. With everyone’s help we may face next year with a bit more information on the best means for deterring deer.