Written By Kris Brown.

Posted on August 2nd, 2022.

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What can landowners do to protect young trees from deer? This blog provides a range of deer exclosure options and cost-share opportunities for family forest owners.

In many areas of New York, it is difficult to grow young trees to maturity because of heavy browsing pressure from white-tailed deer. “So what?” you might ask. We already have plenty of existing forest cover that has grown beyond the reach of hungry deer.

Think about events that might remove existing canopy trees, such as ice or windstorms, insects and disease (e.g., emerald ash borer), or even timber harvesting. What species exist in the understory, waiting for their chance to replace those removed by natural or anthropogenic disturbance?

The answer is whatever is least palatable to deer. Tree species like American beech, hop hornbeam, or striped maple. Invasive plants like Japanese barberry, multiflora rose, or hay-scented fern, which happens to be native to New York. Many shudder to think about this being the future forest condition.

What can landowners do to protect young trees from deer? This blog provides a range of deer exclosure options and cost-share opportunities for family forest owners.

For smaller tree planting projects, you’ll likely need to protect individual trees with tree tubes or tree cages. Later, when trees have outgrown their tubes, you can ‘graduate’ them to bark protectors (also known as tree guards). The bark protectors shield trees from damaging buck rubs. You can learn all about protecting planted trees with tubes, bark protectors, cages, and fences on MyWoodlot.

A tree cage protecting a tulip poplar seedling at Siuslaw Model Forest in Acra, NY.

A bark protector on a river birch sapling at a Trees for Tribs project at Hunter Brook Preserve in Yorktown Heights, NY.

Expect to maintain planted trees annually. Maintenance activities might include things like clearing tree tubes plugged with leaf litter and mouse nests, pruning branches, checking the sturdiness of wooden support stakes, replacing sun-worn zip ties, graduating trees from tubes to bark protectors, and counting the number of live trees to calculate percent survival for your planting project. Here at MyWoodlot, springtime maintenance of Croton Trees for Tribs projects has become an annual tradition.

Next we’ll transition from individual trees to protecting areas of trees. At some point, maybe 0.5 acres or more, it becomes more cost-effective to put up a fence (also known as an exclosure), to keep deer out of areas where you’ve worked hard to improve your woods. These areas might include invasive plant control or timber stand improvement projects. There are a variety of fencing options, but the goal remains the same: keep deer out of your project area for 5 to 10 years to allow desirable trees to grow at least 5 feet tall, when they are more or less safe from deer browsing.

For details about constructing high-tensile and plastic mesh fences, check out the Cornell Cooperative Extension publication entitled Low-Cost Fence Designs to Limit Deer Impacts in Woodlands and Sugarbushes. I learned from this publication that once materials and labor are considered, an 8-foot-tall woven-wire fence can cost $2.50 to $4.00 per lineal foot. Consider this to be an industrial strength type of deer fence. The price is higher, but it is highly effective at keeping deer out.

High-tensile and plastic mesh fences utilize ‘living fence posts’ (i.e., live trees) and are much cheaper at $0.50 to $0.60/foot, respectively. Note that in the case of Siuslaw Model Forest, which has demonstration areas for both high-tensile and plastic mesh exclosures, the plastic mesh has done a better job of excluding deer. The reason being that deer were able to crawl under the bottom strand of high-tensile wire.

High-tensile deer exclosure at Siuslaw Model Forest. Note the living fence post with the batten strip and 8 strands of high-tensile wire.

Plastic mesh deer exclosure at Siuslaw Model Forest.

You may also want to check out the Install a Deer Fence activity on MyWoodlot, where you can find construction tips and considerations, deer fence demonstration sites, and links to deer fencing suppliers.

In yet another example, a landowner recently showed us a low-cost electric deer exclosure for a 0.75-acre food plot. The goal was to keep deer out of the plot until late fall. The fence was low to the ground and involved two strands (one at 1-foot-high and one at 4-feet-high) and an offset strand 3 feet out from the two-strand fence. Supposedly, the offset strands cause a depth perception issue for deer that dissuades them from jumping over the wires. Of course, the electric fence also acts as a deterrent.

Low electric fence with offset strands protecting a food plot.

Solar panel power source (Solar Pak) for the electric fence.

The exclosure was installed in the summer, and by the time we saw it in mid-September, the landowner said no deer had breached it. We did question how badly deer would have wanted to get into the food plot given that there was abundant food outside the exclosure when we visited. The effectiveness of this exclosure needs to be tested when outside food sources are scarce. Nevertheless, the landowner had a simple, portable, and relatively inexpensive design costing around $325.

Like tree tubes, deer fences require regular maintenance to remain effective. Trees fall on them. Deer crawl under them. It’s a constant battle. What if there was a low-cost design that didn’t require maintenance? For the last five years, Cornell Cooperative Extension has been experimenting with slash walls to exclude deer from recently harvested areas. The walls are 20-feet-wide x 10-feet-high, built in conjunction with the harvest from low-value stems and slash near the perimeter of the harvest area. The average construction cost is about $2.25 per linear foot of wall, or about half the cost of industrial-strength, woven-wire fencing.

Profile view of a slash wall deer exclosure at Cornell University’s Arnot Teaching and Research Forest. Each exclosure has an access gate.

Post-harvest regeneration results inside the slash wall.

By all accounts. the walls are highly effective at keeping out deer. At the time of this writing in Dec. 2021, 9 slash walls have been constructed, ranging from 6 to 150 acres. Researchers have yet to find evidence of deer inside the exclosures and this has been a boon for forest regeneration. I had the chance to tour the slash walls at Cornell’s Arnot Forest in late Sept. 2021 and I encourage you to do the same. To find out more, watch this six-minute video and visit the Cornell Slash Wall Resource Center.

So, there you have it. If you are a landowner that is interested in doing a tree planting, invasive species control project, or a timber harvest, hopefully this article helps you find a practical way to protect young trees from deer. Please see below for a list of technical and financial resources available to help you with your tree planting/tree protection projects:

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