Oh Deer

Even though as winter sets in deer metabolism slows and feeding/browsing damage becomes less obvious, deer still manage to cause some major damage to the landscape

A willow, Salix discolor, that has suffered multiple deer attacks, yet has survived. 
The trunk guards were put on after the fact.

Last February I came to the realization that if I wanted to grow new trees, especially conifers, I would need to protect them from the deer, especially the males during mating season. Here in the Mid-Atlantic November brings on rutting season, the time when white tailed deer mate.  During rutting season male deer rub their antlers against trees and shrubs to remove the velvet from the newly grown horns.  They also will rub trees to mark their territory and to take out their heightened aggressions as mating season kicks in.  What deer prefer for this rubbing behavior are trees and shrubs 1-4” in diameter with smooth bark, like willows and magnolias.  Aromatic cedar and other conifers are also favorites.  Once a tree is marked they will often return to the same one.  At one time I had a nice little Canaan fir, Abies balsamea var phanerolepis,  that I surrounded with chicken wire after it had been rubbed a little.  Two days later all that was left was a bare splinter of a tree.  Now is the time to put up some protection to save some of our precious young plants before they are destroyed.  Following are some of the actions I've taken.

Trunk Protection
Last year I tried horizontal fencing for the first time and did not have great results.  It did not protect a young magnolia from rubbing, but a number of small evergreens did not take any damage.  Based on the photos I have, the deer appeared to skirt the areas with fencing lying on the ground. 

The pink flags indicate where I have put 2"x4"welded wire fencing on the ground around this little Canaan fir tree. 
The idea is that it creates unstable footing that the deer don't like.  The flags help me avoid the fence when mowing. 
I want to add some block underneath to lift the fencing further off the ground.

This year I have plastic mesh poultry fencing wrapped around the trucks of most of the stag-susceptible trees.  For others I have a heavier duty  4” drain pipe around the trunk.  (I’m a little concerned about heat build up under these black tubes.  For that reason I drilled ¾” holes every 6”to aid in ventilation.)  I also used some paper tree wrap on some smaller specimens.  One product that looks very good to me is a white spiral plastic.  It looks like it will protect the bark from rubbing and is open enough to prevent heat build up and not harbor insects.  I haven't bought any of that, yet.  A welded wire barrier surrounding the tree trunk has also proven very effective.  This is most efficient with single trunked trees with few lower branches.  Chicken wire may do a good job of limiting browsing but I've seen it ripped away from small trees that had been rubbed by a buck.

I wrapped the trunks of this fringe tree, Chionanthus virginicus, with plastic poultry fencing. 
It's easy to cut and can be tied together with zip ties or wire.  This material should protect the bark,
but will not support the trunk.

Here I am using a spiral cut 4" drain pipe to protect the trunk of this persimmon tree,
Diospyros virginiana.  I drilled holes in it every 6" to reduce heat build up.  This is
pretty tough material and should hold up to attack.

This Sassafras is being protected with a conventional welded wire cage. 
It's been here 4 years, but now it's of prime size for a deer attack. 
Hopefully the large size cage will be a good deterrent. 
I pulled the cage away during the summer to strengthen the trunk.    

Except for the open mesh materials it is a good idea to remove bark protection in the spring.  Heat and moisture build up can damage the bark and in some cases can harbor insects.  Also too much rigid support can keep a tree from developing a strong trunk.  I found this with my young sassafras.  It was getting floppy and the truck was not able to support the top growth on its own.  I pulled away the support this past spring and now the truck is much firmer.

Here  on this willow I'm comparing a variety of protection devices. 
On the right is a paper tree wrap.  Not sure how that would hold up versus a buck.

Repellents
In winter deer’s metabolism slows down, but they are still out there browsing.  Evergreens, branch tips and leaf buds are at risk.  Fencing and cages are effective at keeping deer far enough away to prevent browsing.  Burlap warps that are used to prevent winter burn on arborvitae should also work.  Repellents are also helpful.  In colder weather taste-based repellents have an edge because they do not need to be volatile.  It is often recommended to alternate among different repellants through the season so that deer don't get used to any one of them.   So far I haven't done that.  

Reading about all the different recommendations for deer repellants, as well as deer resistant plants, it has become clear that not all deer are the same in regards to their likes and dislikes. Be flexible and try different recipes and products.  I've had good success using Bobbex which contains a variety of taste and odor deterrents. 

Planning Ahead
I’ve seen a number of people on Facebook ask about starting gardens in areas with lots of deer.  My deer seem to test every new plant that goes in the garden.  For new shrubs I usually put a chicken wire cage around them.  As far as planning an new large planting, I like the advice I’ve read in ‘Deerproofing Your Yard & Garden’ by Rhonda Hart.  She recommends fencing in the new garden space before doing any planting.  This is because deer are creatures of habit.  If they have never found anything of interest in an area, then they are not likely to return.  But, once they have found something tasty there, they will make every effort to return.

On the Bright Side?
Deer browsing results in some unsightly damage to many landscape plants.  It is not uncommon to find hedges of arborvitae and junipers chewed back up to about four feet off the ground.  There are some aspects of deer browsing behavior that could be considered beneficial.  The following two photos show where deer have pruned away branches from the lower 4 feet of a yew and a rhododendron.  This sort of pruning opens up the ground plane for lower growing herbs to fill in. In the absence of deer these would be mounds of foliage.  I've also seen this with spicebush, Lindera benzoin, in the woods. This can happen when there is not excessive deer pressure.  Had there been more deer here say 10 years ago these shrubs may not have grown more than a foot tall before being destroyed, unless they were being protected with cages and repellants.

The lower branches of this yew have been munched away over the years.

This rhododendron has been 'limbed up' by deer.

What methods have worked for you during rutting season?  I'd love to hear about them.