Ask Elaine: Deer Issues in Laurelwood Arboretum

As I stroll through Laurelwood Arboretum, I cannot help but notice the netting around some of the plants.  What is going on?

Thanks for the information and update.
Annie

Dear Annie,

It is a great time of year to enjoy the sights, sounds and smells of autumn. Leaves are changing color, the stream into Laurel Pond is babbling, and the air is fresh and clean. Walk or sit and enjoy the falling leaves, the chipmunks scurrying and the deer munching on the plants. 

Deer in the arboretumYes, we have a large deer herd in Laurelwood Arboretum that are devouring many of our prized plants. Right now, netting is the only way to protect our beautiful garden.

A little deer biology: the average weight of an adult deer is 100-160 pounds. They will consume 6-10 pounds of green plants per day. Deer have a keen sense of smell (their nose size is three times larger than a dog’s).  Deer have superior hearing, 310 degree field of vision, are excellent swimmers, have strong leg muscles for speed (35mph sprint), cloven hooves for traction, natural camouflaged fur, no upper incisors (top teeth) and a 4-chambered stomach.

Deer have a daily “to do” list: graze, rest and don’t get eaten by predators. The deer follow established walking paths thanks to the scent glands between their toes. They stamp their front feet or snort as a warning to other deer (and humans). Deer feed mostly during low-light hours and “on the run” and they face the prevailing wind to pick up any suspicious scents. Their average territory is one square mile (about 700 acres)

Fawns are born in spring (twins!), and are nursed through the summer. Bucks grow velvety antlers in spring and summer (1/2” per day). Antler rub begins in autumn. The rut/mating season is in mid-November. Winter is a slowdown of activity. Male antlers demineralize and drop off in winter. Deer typically live six to 14 years. The latest statistics available (2013) estimates that there are 105,535 deer in NJ (numbers from counties where deer hunting is permitted).

Other interesting facts:

Plant destruction is in the form of footprints, droppings, nesting, eating
            2001 $30 million crop losses in NJ (Department of Agriculture)

Deer-car collisions (State Farm Insurance)
           2013: 26,860 reported in NJ
           2012: 200 fatalities nationwide
           2012: $4 billion in vehicle damage (2001 $38 million in NJ)

Diseases that ticks carry: Lyme, Babesiosis, Anaplasmosis, Ehrlichiosis, relapsing fever, Rocky Mountain spotted fever, Tularemia, tick paralysis, Powassan virus

There are some controls available to repel the deer or protect valuable plants:

  • Repellents that either taste bad or smell repulsive to the deer
  • Startling sights (lights)
  • Offensive sounds (horns, clanging pans)
  • An element of surprise (dog, shooting water)

Some people are curious about deer reduction methods and I can tell you about a few:

  • No poisons are registered and are therefore illegal
  • Trapping and relocating may be performed by state wildlife officials (it has a 21% mortality rate)
  • Hunting – license and permits are available
  • Community based deer management program is conducted through the NJ Department of Environmental Protection, Division of Fish and Wildlife. The program began in 1995. Fish and Wildlife Council reviews applications submitted by municipalities. Culling by authorized agents who pass a shooting proficiency test. Princeton Township, Millburn, Bernards, Bridgewater, Mountain Lakes, Summit, Hanover, Harding, Scotch Plains, and Essex, Hunterdon, Mercer, Morris, Somerset and Union counties, and airports have participated in the program. Venison is donated to a community food bank.
  • Fertility control is costly and not 100% effective
  • Wildlife rehabilitators will take deer and other animals that are injured
  • Deer can be taken to one of 130 Wildlife Management Areas in New Jersey

Let’s consider deer-scaping, plants that are deer resistant. There are a few plants that deer seem to leave alone and they have one or more of the following features: the plant tastes bitter; the plant has a dry, unpleasant texture; tough and leathery leaves; purgative effect; it is poisonous; it has fuzzy leaves or prickles, thorns or spines. Some plants like herbs overstimulate the sense of smell. There is a Rutgers Fact Sheet (E271) entitled “Landscape Plants Rated by Deer Resistance” that may help you landscape your property. Please know that highly resistant plants on list have been eaten at Laurelwood.

installing deer nettingExclusion with the use of netting or fencing is another way to protect plants. Netting can protect groups of plants. Chicken wire around tree trunks protects the bark from deer antler rub. A fence needs to be 8’ tall at least with 12’ posts (4’ deep) since the deer are very agile jumpers. The fence can be non-electric (mesh or wire) or electric (timed pulses from high-voltage, low-impedance chargers). Fencing is a safe, non-lethal, legal, and humane method of deer control.

So how is a public garden like Laurelwood Arboretum going to protect itself from these four-legged ruminant, STATE-OWNED pests? All summer and autumn, we have sprayed repellents on many of our plant collections. Perhaps you have smelled it. Since we had a rainy summer, the repellents had to be re-applied weekly. We use different materials so that the deer do not get used to the repellent. I estimate that nearly $1000 was spent on time and material using repellents. 

We have installed deer-resistant plants only to have them eaten, sometimes right to the ground. Some plants that have shown deer-resistance are ferns, daffodils, ornamental onion, cleome, fuzzy-leaved herbs, butterfly bush, Pieris japonica (andromeda), Callicarpa, boxwood and Mahonia.

Finally, we have resorted to netting our valuable azaleas and rhododendrons. Posts, netting and bamboo poles were installed very closely around groups of plants so that the deer cannot jump in. We started this project last year (2016) on Azalea Way. The enclosed azalea plants were obviously larger and more floriferous in 2017 than the nearby unprotected azaleas. Because of the generosity of the FOLA Board of Directors and several individuals, we were able to expand the netting project to several areas in Laurelwood.  The netting will save the plants from deer foraging and allow the plants to bloom and grow for all to enjoy.

Thanks for your interest in Laurelwood Arboretum.

Happy Thanksgiving.
Elaine Fogerty, Executive Director

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