Sunday, January 23, 2011

Deer Country 7: Protecting Shrubs & Trees with Fencing

Caged tree







How do I protect shrubs and trees that aren’t “deer resistant” from browsing and rubbing? I do it with fencing. I make cages out of posts and wire fencing and have created what I call the Clarksville Shrub & Tree Zoo, where plants are caged and deer run free.


There is one difference of note between shrubs and trees that I cage. The shrubs—by definition woody landscape plants relatively short in height—generally don’t outgrow their need for protection from either browsing or rubbing. Most trees, by contrast, eventually grow tall enough that deer cannot reach their lower leaves and have trunks that are too large for bucks to rub efficiently.  That's why my tree cages generally are smaller in anticipation that trees will outgrow their need for the cages, and my shrub cages are generally larger in anticipation that shrubs will not grow large enough to eliminate the need for protection.


Caged shrubs
After 15 years of trial and error of dealing with bambits here at Meadow Glenn, here’s how I fence my trees and shrubs.


I use light-weight, 5-foot iron posts that I buy at hardware stores, mainly because the 5-footers are reasonably tall and relatively inexpensive. Taller, heavy-duty posts cost significantly more but, of course, are more resistant to bending by the deer.

Yes, deer at Meadow Glenn bend light-weight iron posts at ground level when I use plastic fencing or “chicken wire.” The deer learn that if they lean in on the soft fencing, it gives. They lean in still more to reach more edibles, and at some point leverage bends the iron posts at right angles at ground level. Wooden, aluminum, or plastic stakes often are nearly as expensive as the more resistant iron posts and generally aren't designed for attaching wire.


Deer-wrecked iron post/chicken wire cage
Because deer don’t respect soft fencing, I now use 48”-high welded-wire fencing with 2”x3” squares. Yes, deer still try to reach over or through it, eat any leaf that grows outside, and each year bend a few posts, but in two years no deer has breached the iron-post/welded wire combination. I buy the fencing in 50’ rolls at hardware stores, but 100’ rolls are available. Some stores carry plastic-covered wiring, and others carry rolls without the green plastic. The plain rolls are generally about $15 cheaper, and from a distance, I don’t notice much of a difference. Frugal Gardener.


After lots of trial and error and wrecking early-model cages with my lawn mower, I generally make larger, rectangular cages for shrubs and circular cages for trees, with the fencing beginning about a foot above ground, which gives my Kubota's mowing deck room to cut fairly close without tangling with and wrecking the cage. With five-foot posts and four-foot fencing, protection extends about five feet above ground level.


The "browse line"
Is five feet significant? Generally, yes. Deer browse as they walk through your landscape, usually from ground level up to where they can reach without too much stretching. That upper limit is about five or six feet above ground level and is called—surprise, surprise—the “browse line.” Your goal with young trees is to protect them until their lower limbs are above the browse line so you can remove the fencing. Yes, deer occasionally and awkwardly rear up on their rear feet to reach leaves, but that’s generally when lower food sources are covered by snow and deciduous trees don’t have leaves to tempt deer.

Experience also has taught me that two iron posts per caged tree work better than one iron post and a less expensive plastic or wood post.  The iron posts are designed to have wire attached, and the more stable cage weathers summer and winter storms better and endures deer exploration better.  I've also learned that I should space the iron posts three to four feet apart when I make a rectangular cage for shrubs.  Longer distances between posts yield a more "giving" cage that deer will be tempted to breach.


But don’t forget the second problem—rubbing. Your shrub cages are permanent, so no problem there. But if in time you remove cages from growing trees, remember to protect their trunks until they’re of sufficient size to discourage rubbing. I see rubbing on 3”- to 6”-diameter cedar and tuIip poplar trunks in our woods, though the bigger the diameter, the less chance the tree will be terminally damaged by rubbing. I make trunk protectors from hardware cloth, but plastic protectors of various designs are available commercially.


In Deer Country 8, I’ll focus on deer-resistant shrubs, and in Deer Country 9, I’ll do the same for trees. 

If this is the first Deer Country posting you've read and you want to learn more, I suggest you click on the "Deer" label below.  You'll get a list of posting that have mentioned deer.  I suggest you start with "Deer Country 1" and read your way through the "Deer Country" series.

3 comments:

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  2. Thank you for this information. I live in Washnington, recently I planted two Australian Pine trees about three feet tall. Deer have been in my yard a lot lately. Well they pulled both those pine trees completely out of the ground!

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  3. A great article indeed and a very detailed, realistic and superb analysis, of this issue, very nice write up, Thanks.

    Deer Resistant Tree

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