Source: Jennifer Schultz Nelson (217) 877-6042 Contact: Bob Sampson (217) 244-0225 Extension Communications Specialist e-mail: rsampson@uiuc.edu
Deer and Rabbit Damage
One of the more infuriating experiences for gardeners has to be watching young plants bud with new life in the spring, only to find one morning that some creature has eaten the plants down to the ground, said a University of Illinois Extension horticulture educator.
"How does a gardener know which member of the local wildlife is to blame?" said Jennifer Schultz Nelson. "With a little careful observation, the culprit is usually pretty obvious."
As the line between urban and rural settings continues to blur, humans will undoubtedly encounter the wildlife they are displacing. In the case of rabbits and white-tailed deer, they have adapted well to their human neighbors and may remain in close proximity.
"At the turn of the 20th century, it looked like the white-tailed deer's days were numbered in the United States," she said. "Hunting and deforestation had decreased their population drastically. Fortunately for the deer, hunting was eventually limited to certain parts of the year, and people found increasing value in maintaining forests rather than eliminating them.
"Deer populations flourished and the animals are now extremely common in many areas."
Fragmented forest areas, like parks and forest preserves, may have contributed to the deer population explosion. White-tailed deer prefer to inhabit the edges of the forest, where enough light penetrates to allow smaller herbaceous plants, trees, and shrubs to grow.
"These areas by nature create an enormous amount of this edge habitat, and deer populations rise up to fill it," she said. "Housing developments are often adjacent to forested areas, making it all too easy for deer to wander over to a landscaped yard and discover the delicious plants there."
Another animal that has adapted well to human development is the common or eastern cottontail rabbit. These herbivores will quickly populate any environment that can offer food and shelter.
"The average backyard usually provides both," said Nelson. "A pair of rabbits taking up residence there will potentially produce up to four litters of young per year, with as many as six young per litter."
But how do you tell which critter has been munching in your garden?
"Take a good look at the damage on a given plant," explained Nelson. "Rabbit damage looks like someone went crazy with prunes, each branch or shoot cut cleanly at 45 degree angles. Rabbits accomplish this feat with their powerful incisors.
"Deer, on the other hand, lack upper front incisors and so grab and pull at vegetation they want to eat. The ends of the remaining branches and shoots are jagged and, if they are small enough, plants may be totally pulled out of the ground. Deer also only eat what they can reach, which is only about eight feet high. They also damage young trees over the winter by rubbing their antlers on the bark."
Other clues which may be helpful are tracks--deer have hooves cloven into two halves, rabbits have distinctive pairs of tracks for the front and hind feet, respectively. Rabbits will often construct grass-lined areas called "forms" to offer some protection on the ground.
"Deer and rabbit damage is most noticeable in the spring and early summer before much plant growth begins," she noted. "Usually deer and rabbit damage to landscape plants is worse in years with colder winters and more snow cover as other nearby food sources run out."
In managing deer and rabbit damage, homeowners need to do their homework, she emphasized.
"There are plants that both deer and rabbits love, and there are plants that they will only eat if it is the last green plant available," she said. "Generally speaking, both deer and rabbits will avoid any plant that has a lot of sap or a lot of scent. There are many plant lists available in books and online listing plants resistant to feeding by deer or rabbits or both.
"Of course, there are exceptions. Sometimes even a plant touted as something deer will never eat will sometimes get eaten in the right circumstances. Nature is seldom absolute."
Using scent or taste repellents for deer and rabbits is usually a viable option for homeowners. These may need to be reapplied after rain or extended periods of time. It is also a good idea to rotate among several different repellents to minimize the chance that the animals will get used to a particular scent.
In many cases, excluding deer and rabbits with fencing is a good option. Electric fencing to deter deer is recommended only in extreme cases, but is not an option for most people in suburban areas.
"Though deer can jump 12 feet high, eight-foot high fences are generally enough to keep them out," she said. "If the area being fenced off is less than about 15 feet wide, six-foot high fences are adequate. This is because deer have poor depth perception, and are hesitant to jump into places that they perceive might be too narrow.
"Another way to take advantage of this is to place two shorter fences a few feet apart. Unable to judge the distance over both fences, often deer will avoid the area.
Rabbit fencing only needs to be about two foot high, and have a few inches buried under the soil to prevent rabbits from digging under the fence, she said. The openings in the fence materials should not be big enough for the rabbits to fit through.
"In many cases, it can be difficult, if not impossible, to prevent all damage from deer and rabbits," said Nelson. "Some damage is inevitable in many locations. In these cases, it may be helpful for homeowners to work on tolerating at least some damage to their landscape."
