GARDEN GODDESS: Oh deer! Mammal pests in the garden

IMAGE: This buck is a frequent visitor to the Takoma Park backyard of Randall Cleaver and Beth Richwine. Photo courtesy of Randall Cleaver.


Gardening ecologically in the Washington, DC, region can be a challenge. We plant native plants and then complain about the native animals that come to munch on them. We can hardly be miffed at Bambi and Thumper, when we have planted a virtual gourmet banquet of their favorite treats for them. Yet, we still want to garden and not have just stubble and bare sticks in our landscape. So how can we garden alongside wildlife and still have a decent-looking yard?

First, we need to judiciously pick our battles. Clearly, if you are growing edibles, then you want to devote more of your time and resources to protecting them so you can maximize the harvest you get to consume. Next on your list will be to protect those ornamental plants that have sentimental or other value for you. Finally, you will want to preserve those plantings with intrinsic property value.

The main line of defense against mammal garden pests is exclusion. Fence off your entire property or just that portion you want to protect. If you are aiming to keep out deer, then the fencing needs to be at least eight feet high. Under most of the local governments and HOAs in the DC suburbs, the maximum allowed solid fencing is six feet high. Therefore, you will need to get creative. You can string fishing line or electrified wire at two-foot intervals along sections of your property that are not crossed regularly by humans. You can also look into mesh deer fencing, which is a flexible net-like material. At a distance of 20-feet or so, it is practically invisible to the human eye. If you do use the mesh deer fencing, make sure you do not leave a gap at the bottom as deer can go under just as well as they can go over. All fencing also requires regular maintenance and repair against things such as tree limbs or snow that can weigh down or break a fencing section.


Photo by Bill Brown.

The next line of defense is natural predators – that can include encouraging our pet cats and dogs to take care of rabbit, voles (meadow mice), chipmunks, and rats. Some of our domestic pets are skilled hunters, while others are not. You may also not be comfortable with this tactic. A more acceptable tactic for many is to use predator urine sprays and granules. Brands include Shake-away and Bobbex. These sprays contain urine from natural predators like bobcats and coyotes. You can also sprinkle blood or bone meal to deter mammals feasting on your garden beds. Milorganite is a fertilizer that is derived from human sewage waste and has proven effective at repelling deer predation. All of these sprays need regular re-application as they can fade away and heavy rains can wash them away.

The other kinds of spray program you can try is organic, sulfur-based brands like Liquid Fence or Deer Out. These are “bad taste” sprays that you apply to the foliage of plants that you do not want deer or rabbits to nibble on. They also can contain hot pepper extras and mint essential oil. Whatever spray brand you choose, know that animals can habituate to certain smells and that you may want to switch up to a different brand very three-to-six months to keep them on their toes.

One proven technique to keep all kinds of mammals from your gardens is a motion-sensor sprinkler system (Havahart and Contech Scarecrow are two popular brands). These shoot out a burst of water at anything that interrupts the motion sensor. It can be quite shocking and a great deterrent. Unfortunately, this works equally as well on humans, so you or a guest can be zapped by a water stream and it can be an unpleasant experience. I always caution those who use this technique to move the sensor around every few weeks, but to put a note on their door to remind themselves and the rest of their household of where they last put it, so they don’t get sprayed as they head out in the morning.

Finally, pick plants that are less palatable to your problem creatures. Deer hate fuzzy leaves like most of the culinary herbs – from lavender to sage. Strong-scented plants like catmint, horseradish, and hyssop repel deer. They also do not like those that are bitter because they are poisonous, those include daffodils, hellebores, lily of the valley and foxgloves. They also find turn up their noses as some native plants like Paw Paw tree and Serviceberry. Use these plants to create a buffer zone between the deer and those plants that they love to consume like hostas and tulips.

Our mammal friends often make gardening frustrating, but it does not have to be an all-or-nothing affair. With proper planning and selection, we can garden and live alongside our native creatures.
A Side Note on Harmless Mammals
The following mammals are harmless and often actually beneficial for your garden: opossums, raccoons, skunks, coyotes, fox, and moles. All of these mammal visitors to your garden will eat slugs, bugs, and small vermin. They should be welcomed, or, at least, not interfered with, as they visit and take care of other pest problems for you. Some of these mammals, particularly raccoons, can be destructive and messy, but they should not be a major issue for you unless you are not practicing good garden hygiene. What does that mean? That includes cleaning up all fallen and rotting fruit and berries, not leaving out pet food, cleaning up pet waste, and storing seeds, trash, and organic fertilizers in metal containers.


This article originally appeared in of Washington Gardener magazine in slightly different version.


About the Author

Kathy Jentz
Kathy Jentz is editor of Washington Gardener magazine and is a long-time DC area gardening enthusiast. Washington Gardener is all about gardening where you live. She can be reached at @WDCgardener on Twitter and welcomes your local DMV gardening questions.