By Bruce Pankratz – Why should you know about protecting trees from deer? Well, somewhere along the line you have probably heard someone say “the best time to plant a tree is 20 years ago.” You might think that means trees take a while to grow tall. Sometimes this is true, but where we live it means 19 years ago you had to replant the tree because a deer ate the first one, so 18 years ago you could plant a third tree to replace the second one a deer ate, and on and on. Twenty years later you may have given up on the idea of ever growing that tree unless you found a tree that deer do not like to eat. That is where protecting trees from deer with tree shelters and cages comes in. Instead of building a fence around your entire woodlot you put a small fence, cage or plastic tube around each tree. Tree shelters work only on trees with leaves and not needles, but cages work with either. You will usually need to buy the plastic tubes called tree shelters. You can make tree cages yourself with fencing.
Keeping deer out of gardens is one thing, but protecting trees from deer is entirely another. Tree cages or tree shelters are meant to keep deer from eating the top of the tree. There have been oak trees on our land perhaps 10 years old but only about three feet tall covered with nipped-off and dead branches. After pruning the trees and putting them in a tree shelter, the trees grew nicely since there was already a good root system in the ground. Some are now 25 feet tall or more. If we hadn’t learned about protecting trees from deer with cages and shelters, we wouldn’t be eating apples from the crop this year.
Protecting Trees From Deer: Tree Cages or Tree Shelters?
When you’re protecting trees from deer using tree cages or shelters, take a look at the differences between the two before making your decision. Tree cages and shelters differ in price, with the tree shelters I have used being more expensive. Unlike the shelters, deer can eat the branches as they grow through the sides of the cages, but deer usually have left the top of the skyward-growing tree alone for both shelters and cages. Once the top of the tree grows beyond the top of the shelter or cage you can set the tree free by removing the cage or shelter. You can then reuse the cage or tree shelter. After liberating the tree you can prune the bottom branches (don’t take too many at first) and a few years later all of the messy bottom of the tree has disappeared as the tree grows wider. Losing the branches at the bottom of the tree is better than no tree at all when you’re protecting trees from deer.
Let’s take a closer look at commercially available tree shelters first. A commercial tree shelter looks like a piece of plastic stove pipe so they are easier to see than cages. The wind pushes on the entire shelter so they must be anchored more firmly than cages. Shelters are sold with one-inch oak stakes. Shelters create a warmer and moister climate so the tree inside can grow faster than in a tree cage. Irrigating the tree means pouring water down into the tube.
To install a shelter simply push it over the tree. With nibbled trees, you may need to prune enough of the tree off so the shelter fits. Next, slip the stake through the plastic fastening strips on the tube that will hold the tube to the stake, pound in the stake and then pull the fasteners tight. Leave the tubes touching the ground in the summer—raise the shelters in the fall to let the tree harden up for winter and then lower the shelters again to keep the mice out. Keeping mice out is something the tree cages cannot do.
Shelters for protecting trees from deer come in different heights. The smaller the shelter the easier for a deer to nibble off the top of the tree and stunt its growth. For us, the best height has proved to be five feet. We tried some three-foot shelters but many were knocked over or gnawed by bears back in the woods. We were able to reuse them a few years ago to protect small oak with better results, but still, think five feet is the minimum to be safe. Once the growing tree spreads its branches too much after it successfully grows above the shelter, you cannot pull the shelter off and reuse it, but if left on the tree, the shelters eventually decompose.
Tree cages, in contrast, last a good long time and probably will have the bark grow around them if not removed in time. You can take the cages apart to get them off of trees if needed.
The best luck we’ve had with the tree cages we built ourselves was to start with a five-foot roll of homestead fencing, costing about $41. We get about 17 or 18 cages from the 50-foot roll of fencing. For a cage with a diameter of about 11 inches, cut a five foot by about 33-inch piece. The diameter of the shelter is roughly one-third (Pi to be exact, from geometry) of the circumference of the cage. When you cut the fence be sure to leave wire for attaching the cage together after you roll the fence piece into a cylinder. Once you have the cage built all you need do is put it around a tree and pound some stakes to keep it steady. Three-foot wood lath (costs about 10 cents each) works to hold the cage. Thread the lathe through the cage from the outside at the bottom, pound it in and then weave the top of the lathe back through the fence. There is not as much wind pressure on fencing compared to tree shelters and also the tree itself helps hold the fence when the branches grow out.
For people who are practicing simple homesteading and have only a small number of trees to protect, cages or shelter may make sense, but if you are trying to grow thousands of trees for income the idea of shelters may not. In any event, you may only know if you made the right decision 20 years from now.
Do you have practical, useful, and effective ideas for protecting trees from deer? We’d love to hear your methods for growing healthy trees!
Originally published in the May/June 2010 issue of Countryside & Small Stock Journal and regularly vetted for accuracy.