donnan.com
29 years on the world wide web!

Lawn & Garden Store
Purchases support this website!

  

Deer damage to Trees & Shrubs


White-tailed deer are becoming much more common around home landscapes as their natural habitat continues to disappear.  To the chagrin of many homeowners, deer are quite comfortable wandering about their landscape browsing on foundation plantings, flowers and vegetable gardens. Some deer control methods seem to work temporarily but then begin to fail.

deer browsing in the suburbs of Pittsburgh

Other homeowners enjoy entertaining deer in their yards with salt blocks and food, even going so far as to attract them with dried cracked corn which is sold at most feed stores. Solutions to the deer problem are difficult and varied, in fact some residents don't consider deer to be a problem at all. Arguments in favor of preserving the deer population focus on their natural beauty, a right to share the land with people and an aversion to deer hunting.
 


Proponents of deer control are concerned about damage to their ornamental and garden plants, the injury and property risks involved with hitting deer on highways and the argument that overabundant deer populations will lead to their starvation in the winter due to a lack of adequate plants for deer browse.


 


These Arborvitae were damaged by deer browsing on the lower parts
  


Hear from some deer experts in this video:
 

 

Deer & Deer Management
in Developed Areas
- Facts & Fiction -

Source: Pa. Game Commission

  • In a healthy population, female deer can breed as fawns (6-7 months of age) producing young at 1 year of age. Average pregnancy rate of doe fawns in developed areas is 40%.
  • Healthy adult does most often produce 2 fawns annually.
  • Removing deer from a healthy population will NOT increase reproductive rates of the remaining deer. Deer in Pennsylvania breed once a year. Average reproductive rate for adult does in developed areas in Pennsylvania is 1.8 fawns/adult doe with 15% producing 1 fawn, 79% producing twins, and 6% producing triplets. Reproduction in females is already close to maximum.
  • Deer can live up to 18 years of age.
  • Deer populations can double in size every 2-3 years.
  • Deer eat about 5-10 pounds of food daily.
  • Deer home ranges are relatively small in urban areas (100-300 acres).
  • Current birth control practices are costly and ineffective in controlling free-ranging deer populations over a large area.
  • Hunters can assist landowners at no cost.
  • Landowners can impose additional hunting restrictions on their property.
  • Homeowners can waive the 50-yard archery or 150-yard firearm safety zone.
  • Hunting does not increase deer-vehicle accidents. During fall, deer naturally move more due to increased activity associated with breeding season. Investigations have shown deer-vehicle accidents occur more frequently on Sundays when no hunting is allowed than on Saturday (high hunter participation day) and 1-4 hours after dark which is after hunting hours.
  • Landowners who allow the use of their property without a fee are protected from liability.
  • Typically, the removal of 1 adult doe during the hunting season equates to 3 less deer the following spring.
  • All deer management programs require long-term maintenance.

  


EXTENSIVE DCNR STUDY OF FOREST VEGETATION SHOWS DEER EXACTING HEAVY TOLL IN MOST AREAS

Browse Monitoring Uncovers Troubling Data in Pennsylvania State Woodlands

March 22, 2007
Press Release
State of Pennsylvania

HARRISBURG — Preliminary findings from ongoing, extensive state forest studies of the effect of white-tailed deer populations on woodland regeneration show habitat damage is the heaviest in the north central and Pocono Mountains areas of the state, Department of Conservation and Natural Resources Secretary Michael DiBerardinis said today.

“Like our past surveys from the air, this unprecedented study on the ground of what deer eat, or browse, is proving to be an invaluable tool in understanding deer densities and distribution in our state forestlands, and it is guiding future DCNR efforts to ensure forest regeneration and healthy habitat,” said DiBerardinis.

“And, like those aerial counts, these browse-study findings are just a single snap-shot in time, incapable of documenting whether forest habitat health is improving or declining. They will, however, provide a meaningful baseline to compare in future trend analyses.”

The browse studies, which were conducted last year and covered almost 90 percent of the state forest system, showed findings the secretary deemed “troubling.”

“Across the entire state forest system, less than 25 percent of the 41,650 plots showed desirable regeneration, and almost 45 percent of the plots lacked any new, woody growth,” DiBerardinis said. “The problem is more acute in the state’s north central ‘big woods’ section where almost 50 percent of the study plots show no woody regeneration and only about 20 percent desirable regeneration.  The most severely browsed habitats were documented in the north central and Pocono regions of the state.

“For these reasons, it would be premature to draw any conclusions that would support an increased deer herd, even in areas where we observed relatively low-browse damage,” DiBerardinis said.

The secretary applauded the commitment of Bureau of Forestry personnel from 19 of the state’s 20 state forest districts who undertook the browse studies during early spring in 2006.

“Never has there been an undertaking of this magnitude in which data from 1,600 miles of transects was entered into the bureau database for analysis,” said DiBerardinis. “These researchers are foresters first, but they also are hunters and naturalists and all are dedicated to restoring forests to a healthy level where deer and other wildlife have sufficient food and cover.”

“We will use this detailed vegetation analysis in conjunction with past aerial surveys to help guide our management decisions and adjust our efforts to steer hunters to certain state forest areas in the 2007-2008 hunting season,” DiBerardinis said.

Transects, which are lines for ecological measurements, were spaced two miles apart.  They were sampled by visiting vegetative plots every 200 feet, recording woody species, and assigning a browsing category to that species at that plot.  Also, presence or absence data was recorded for “desirable” and “undesirable” woody vegetation at every plot. 

Woody plants include trees, shrubs and vines. Woody plants dominate the vegetation wherever conditions are favorable for plant growth.  Deer feed on the leaves, twigs and buds of these plants.

Other survey findings include:

  • Data gathered aided in development of a preliminary deer-browsing preference index for woody species observed, which will help guide future monitoring efforts and provide browse intensity indicators;
  • Across the state, the proportion of plots with desirable regeneration (24.45 percent) and lack of woody regeneration (44.45 percent) indicate browsing has not been suppressed long enough for a widespread regeneration response;
  • Identifying browsing impact from lowest to most severe, the Forest Districts ranked as follows:  relatively lightly browsed with better regeneration — Lackawanna, Buchanan, Michaux, Tiadaghton, Tuscarora, Gallitzin, and Cornplanter; relatively moderately browsed with less regeneration — Moshannon, Susquehannock, Rothrock, Forbes, Bald Eagle, and Tioga; relatively severely browsed with poor regeneration — Weiser, Kittanning, Wyoming, Sproul, Delaware and Elk;
  • Monitoring will continue to locate other areas of continued excessive browsing where deer harvests should be increased, and these efforts will be coordinated in the State Forest Management Plan.

Details on the 2006 state forest deer browse study, as well as DCNR’s aerial surveys and other information on deer, can be found online at www.dcnr.state.pa.us and select “State Forests.”


Deer Rubs

Bucks mark their territory by rubbing tree trunks with their foreheads and antlers to apply a scent from glands in their foreheads, causing extensive damage to tree trunks.

buck rub damage during the rut

 

Deer Damage on a Weeping Cherry trunk


December 2003 Report

There were 2,079 reportable vehicle-deer collisions in Pennsylvania (crashes that result in bodily injury or major vehicle damage) during 1991, compared to 2,532 in 2001. This is an increase of 21% over that ten year period. 
   
12 people were killed in these accidents during 2002, which is triple the number of deaths from the late 1990's. 
   
The Pennsylvania Game Commission estimates 45,000 to 60,000 dead deer are removed from state highways annually.

2001 Deer Harvest - W. Pennsylvania

County

Antlered Antlerless
Allegheny

3,098

6,720

Beaver

2,118

4,204

Butler

4,834

6,223

Fayette

2,934

3,729

Greene

4,196

7,258

Indiana

5,446

6,848

Washington

6,225

10,833

Westmoreland

5,810

7,698

Source: Pennsylvania Game Commission

  

Allegheny County & Washington County
Harvest Statistics 1993-2002

   
Allegheny County Harvest Statistics
Source: PA Game Commission

YEAR ANTLERED DEER ANTLERLESS DEER
1993 1,852 4,431
1994 2,089 5,129
1995 2,344 6,751
1996 1,975 5,375
1997 2,133 5,455
1998 2,287 5,398
1999 2,191 5,405
2000 2,675 6,416
2001 3,098 6,720
2002 3,693 6,577

Washington County Harvest Statistics
Source: PA Game Commission

YEAR ANTLERED DEER ANTLERLESS DEER
1993 3,807 6,087
1994 4,267 5,829
1995 4,717 6,213
1996 4,550 5,419
1997 5,025 5,640
1998 5,718 5,801
1999 5,760 5,467
2000 6,495 8,290
2001 6,225 10,833
2002 3,743 11,193

 


Upper St. Clair planners have discovered one of the few places deer will leave tulips alone - a traffic island!
   


CONCLUSIONS

Wherever one stands on the deer issue, gardeners these days must be VERY conscious of potential deer damage if they hope to have much success at all with their gardening activities.  There are basically three strategies:
   

  • EXCLUSION - Through the use of fencing or mesh, keeping the deer away from plants.  Effective deer fencing needs to be 6 to 10 feet high, depending on the exact location. There are also some plastic meshes available to drape over top of desirable plantings.  Some of the newer meshes and fences are difficult to see, adding to their desirability as a viable alternative.

Plastic mesh can be draped over
plants to prevent deer browsing


   

  • DEER REPELLANTS - There are several commercial products and "home brews" that can be sprayed on plants to discourage deer browsing.   The main disadvantage is that sprays need to be reapplied on a regular basis, and even more frequently during wet weather.


Deer stay away from Boxwood!
  


  • PLANT CHOICES - Deer have "food favorites" just like us.   Lists are usually broken down into categories of desirability.  However, it's important to remember that deer will eat ANY PLANT during a severe winter when other browse is scarce.  Listed below are some of the most commonly known plants:

  1. High browse risk:
    Arborvitae, Daylilies, Euonymus, Hosta, Tulips, Yews

  2. Low browse risk:
    Trees - Ash, Beech, Birch, Colorado Blue Spruce, Dogwood, Elm, Gingko, Hawthorn, Honeylocust, Larch, Linden, London Plane, Magnolia, Maple, Oak, Redbud, Spruce, Sweetgum, Tulip Tree, Willow, Zelkova
    Shrubs - Barberry, Bayberry, Boxwood, Cotoneaster, Drooping Leucothoe, Forsythia, Hydrangea,
    Japanese plum yew, Junipers, Lilac, Mahonia, Mugho Pine, Pieris Japonica, Potentilla, Privet, Pyracantha, Russian Olive, Spirea, Viburnum, Weigela
    Other
    - Ageratum, Ajuga, Aster, Astilbe, Tuberous Begonia, Bleeding Heart, Purple Coneflower, Crocus, Daffodils, Dahlia, Blue Fescue, Foxglove, Gazania, Geranium, Iris, Lavender, Lamb's Ear, Calla Lily, Miscanthus, Pachysandra, Peony, Creeping Phlox, Poppy, Rudbeckia, Salvia, Sedum, Snapdragons, Strawflower, Verbena, Veronica

NOTE: Rabbits WILL browse on some plants which deer leave alone.  When protecting a plant from rabbits in the winter, be sure to allow for "added reach" due to snow depth acting as "elevator shoes" for the rabbits.


Deer question from Sandy's Garden

Q. I have a privacy row of hemlocks that the deer have browsed up to about seven feet - which means they no longer provide as much privacy! Can you recommend an evergreen shrub that would fill in the bare area AND not provide the deer with more delicious meals? The shrubs would be planted close to, but not directly under the hemlocks, and the area will be quite shady.
  
A.
You do have a challenging situation, because broadleaf evergreens that tolerate shade such as rhododendron and mountain-laurel tend to be favored by deer, while most needled evergreens prefer more sun. Hemlocks are one of the most shade-tolerant needled evergreens, but a little too tasty for Bambi. The only plant that really comes to mind in your situation is Japanese plum yew, Cephalotaxus harringtonii. It tolerates shade, and is considered to be quite deer resistant.
  
It is not a well-known plant in our area, but that is changing because it is such a tough, durable plant and because it seems to be very deer resistant. It will be a little hard to come by, although your local nursery may be able to order them for you. The only other drawback is that they are slow growing and will not fill the gap in your privacy hedge as quickly as you might wish. The straight species grows five to ten feet tall with a similar or slightly greater spread. They can be sheared into a formal hedge or allowed to grow naturally; whichever suits your landscape best.

More columns from Sandy's Garden



An attractive wrought iron guard protects this newly planted tree from deer shredding the bark on the trunk with their antlers during the fall "rut"


MORE

Protect your tree trunks from deer

Deer rubs on tree trunks

Trophy whitetail bucks

 

     


home | terms of use | contact | search | site map
lawn & garden store
Copyright ©2017  DONNAN.COM  All rights reserved.