Tuesday, May 10, 2016

Prevention of Deer, Elk and Rabbit Damage to the Home Landscape by Peter J. Drake

Photo courtesy nps.gov
Whether you are justifiably proud of your long-standing, carefully-nursed hedge and flower beds, or you are just starting out in shaping your home yard into the plantscape of your dreams, you have probably already confronted, worried about, and tried to deal with wildlife damage—particularly, for Colorado at this time of year, the damage resulting from activities of deer, elk and rabbit.

While prominent in the wild, and often infiltrating residential areas, you do not have to resign yourself to continual replanting and repair of seasonal destruction.  You do have the ability to mitigate damage, and preserve your plants; and you can accomplish this through the consistent, year-to-year practice of a few techniques of landscape protection.  These are: use of fencing, application of repellents, and utilizing plants which are not preferred by these animals.  Let’s review each of them, in turn:

Consider fencing. A fence, properly constructed, is the only truly secure barrier you can provide for an area you want to protect.  It needs to be properly scaled for the type of protection you want to provide.  A fence to protect your plants against rabbits, for instance, should be of a stout material like 1 inch galvanized hardware cloth, set between 18-24 inches tall, and extending for 6 to 8 inches underground, to discourage both jumping and burrowing.  Fences for protection against deer and elk would not need to extend underground, but would need to be at least 8 feet high and, for best effect, of either woven wire construction, topped with barbed wire, or high-tensile electric fencing.

As any kind of fencing, of course, represents a significant investment of time and money, it is probably best to focus on the protection of small spaces, and specific plants.  A collar of 1 inch hardware cloth, of solid polypropylene, or a similar pliable barrier material is suitable to deter rabbits, deer and elk from a particular tree and shrub—provided the height of these collars are scaled appropriately: 18 to 24 inches for rabbits, 8 feet for deer and elk.

Utilize repellants. Repellants, widely available commercially in liquid and granular form, include formulations of hot pepper oils, fermented eggs, predator urines and ammonium salts.  They can be applied in a perimeter around areas of yard you would want to protect, or (depending on the specific product) directly on plants.  

Important factors to bear in mind about repellents are that (1): They must be periodically re-applied—this can range from once every 30 days, or after every rain, or plant watering, depending on the product; (2): Repellents are only a deterrent.  They do not render any plant “proof” against deer, elk or rabbit.  If these animals are hungry enough, they will still at least try nibbles of what is most attractive to them.  At this point, then, repellents are best considered as used in tandem with our third recommended practice: utilizing resistant plants. 

Plant undesirables. Deer, elk and rabbit, while all herbivores, have certain, preferred tastes.  Generally, deer prefer to browse on grasses, perennial flowers and shrubs, elk prefer grasses and forbs, as well as the newer growth of shrubs, and rabbits prefer grasses, herbs and (when these are not available) tree and shrub bark.  Lists of plants which are less attractive to each of these animals are readily available, maintained by such organizations as the Colorado State University Extension Service.  Resistant choices for deer include Colorado spruce, hackberry, creeping thyme, and grape hyacinth.  For elk, hawthorn, barberry, daffodil and blanket flower are possible choices.  Resistant choices for rabbits include sedum, foxglove, blue mist spirea and iris.

It is important to remember that any plant “resistant” to being eaten by deer, elk and rabbit are not “proof.”  As I have already stated: if any of these animals are hungry enough, they will take advantage of what they regard as edible.   

It is, in conclusion, important to remember that the best way forward, in minimizing deer, elk and rabbit damage to your landscape, is to apply a combined approach of fencing off what you most want to protect, spreading repellents on or around what you want to direct a hungry animal away from, and using less-appetizing “resistant” plants in the landscape.  All of these practices, continued year after year, can help reinforce to migrating animal populations that yours is not the place they want to stop for a bite, and it is best for them to search elsewhere.

FOR FURTHER READING, PLEASE SEE:

Johnson, Heather E. et al. Evaluation of Techniques to Reduce Deer and Elk Damage to Agricultural Crops. Wildlife Society Bulletin; DOI: 10.1002/wsb.408