Deer Problems

The section that exists to stop you spending

Every other cluster on this site sells you a response. Fencing sells a barrier, deterrents sells a spray, garden design sells a planting plan. This one sells nothing. It exists to work out what is actually happening in the garden before any of that money leaves your hands.

The commonest expensive mistake in this subject is not the wrong fence height or the wrong repellent. It is building an eight-foot deer fence around a garden that rabbits are eating. A square quarter-acre is about 420 feet of perimeter, which at eight feet means mesh, posts, bracing and a gate that all have to be right. The rabbit answer is two feet of chicken wire with the bottom six inches bent outward into an L, run around one bed rather than the boundary.

The test that separates those two outcomes takes about ten seconds. It is in the next section.

The torn stub settles most of it

Deer have no upper incisors. They grip a shoot between the lower teeth and a hard upper palate and pull. Every identification sign in this section follows from that one piece of anatomy.

A deer-browsed stem ends torn. Ragged, shredded, fibres pulled apart rather than severed. Rabbits and rodents have upper incisors and cut like scissors, leaving a clean face angled at roughly 45 degrees.

Look at the end of the shoot rather than at the plant as a whole. That is the entire method, and it is why this is worth doing before reading anything else here. Identifying deer damage covers the rest of the signs, tracks and droppings and what a browse line is telling you, but the stub decides most cases before you get that far.

Bark is the second clean separator, and it earns its place in winter, when the browsed shoots are long gone and the bark row in that table is all you have left to read.

Height narrows what is left

Deer feed from the ground to about six feet. Rabbits work below about two and a half. Height on its own will not confirm deer, because deer feed at rabbit height as well, but it rules them out cleanly in one direction: damage confined below knee height is rarely deer.

The reverse case is properly diagnostic. Damage running up to five or six feet and then stopping in a flat ceiling across a hedge or a woodland edge is deer and nothing else. Forest ecologists read population pressure off exactly that line, and a hollow understory under an intact canopy means the herd has outrun its food.

Snow moves the ceiling. Two feet of settled snow is a two-foot ladder, and the band of hedge that was safe last winter is not safe this one. The same mechanism is why rabbit bark damage arrives as a stripe rather than a patch. The stripe records where the snow was.

Five other animals get blamed on deer

If the damage is below knee height, it is probably one of these, and the fixes are mostly incompatible with each other. Rabbits take whole young stems off at a clean angle and strip bark at snow height with visible tooth grooves. Groundhogs remove whole plants at ground level overnight, usually in a vegetable bed, and leave a burrow entrance 10 to 12 inches across with a mound of excavated soil against a shed or a fence line. Voles do all their work underground: the plant wilts for no visible reason, then lifts out with no roots left, and the tell is a quarter-inch hole with no mound. Squirrels dig up freshly planted tulips and crocus within days of planting and ignore daffodils, which is why daffodils solve two problems at once. Slugs chew holes through the leaf rather than removing it, which matters because they are worst in damp shade, which is where hostas grow, which is where deer damage gets assumed.

The distinction between slug and deer damage is the one worth memorising: if the plant looks lacy, it is slugs, and if the plant looks shorter, it is deer. Rabbits, groundhogs and voles has the signature, the tell and the fix for each, including why a groundhog is harder to exclude than a deer. A groundhog fence needs to go about 12 inches underground and carry a floppy, unsupported top, because a rigid fence they can grip is a ladder.

Damage that is not feeding at all

Bark shredded vertically on a young trunk, roughly one to four feet up, with the wood scored underneath, is a buck rubbing his antlers in autumn. That is deer, but it is not browsing, and the difference decides the response. It girdles young trees and kills them, usually the following summer for no visible reason. A trunk guard fitted before autumn prevents it. A repellent does nothing, because the animal is not eating.

Flattened areas in long grass or a bed, repeated in the same spot with browsing nearby but not on the flattened plants, are bedding rather than damage.

Some damage is telling you about the herd, not the garden

Deer eating spruce, fir or pine needles is a signal worth reading properly. Those needles made up 58 to 60 per cent of the rumen contents of starved deer autopsied in late winter during past population peaks. In healthy deer they are a minor part of the winter diet. Deer eat them when there is nothing else, so needle browsing means the local population is under real pressure, and plant choice alone will not fix that garden.

Arborvitae is the exception and does not carry the same meaning. Its foliage is genuinely preferred, outranking deciduous twigs and every other conifer, which is why American arborvitae is one of the fourteen Rutgers-rated plants in the worst tier of the plants to avoid. Western arborvitae is rated a tier below it, which is worth knowing before you assume the genus behaves as one thing.

Wait until mid-June before cutting anything out

Once the damage is identified, the next question is what survives it, and the answer splits hard by plant type rather than by how bad it looks.

Conifers mostly do not come back. Arborvitae, spruce, fir and juniper carry no dormant buds along older stems, so foliage stripped below the browse line does not return on that wood. What you get instead is a permanently bare lower section under a healthy top that keeps growing out of reach. Yew is the one needled exception, holding dormant buds on old wood, though that is a recovery trait rather than a recommendation: Japanese yew is rated frequently severely damaged. Broadleaf evergreens usually recover, boxwood and holly among them, and deciduous shrubs almost always do, losing a season of shape rather than the plant.

The practical rule is to wait. Buds on arborvitae and juniper are hard to see, and a branch that has produced nothing by mid-June is dead. Anything cut out before then is a guess you cannot reverse. When you do cut, cut the torn stub back cleanly to a bud, because a pruner wound heals far better than the ragged one a deer leaves.

How to judge the evidence, including ours

Most gardening sites do not tell you how to weigh their own evidence. This one does, and how to judge deer research is probably the most useful page here for anyone who has already read three contradictory articles and wants to know which to believe.

The argument is that deer evidence comes in three kinds and they answer different questions. Practitioner consensus is a committee of professionals agreeing on ratings: cheap, broad, unverifiable. Captive pen trials use known deer and measured food, which is precise, and the animals are penned and often hungry. Field studies use real plants and wild deer, which is realistic and much noisier. Confusing the three is where most bad advice comes from. Two Connecticut studies on predator urine reached opposite verdicts because the 1991 work sprayed the substance onto foliage weekly and the 2010 work tested commercial products as sold. Both were right about what they measured. Only one describes what you can buy, and the gap is not small: the coyote urine that earns a high rating in Colorado's table is 100 per cent undiluted, where a registered product contains 3.5 to 5 per cent.

The four-tier scale this site uses is the first kind, and it says so. It was compiled with input from nursery and landscape professionals, extension personnel and Master Gardeners in northern New Jersey. It is not a feeding trial and it names no deer species anywhere, so read it as white-tailed guidance. It carries local assumptions too. Rosemary is rated rarely damaged, and rosemary is hardy to about zone 8. In the zone 6 gardens the list was compiled in it is a pot plant that comes indoors in October, so the rating describes a shrub that most of its own audience never leaves outside. That is a hardiness fact from one state riding along inside a deer rating, and it travels nationally without a label.

Which raises the question this page has to answer about itself. The encyclopedia holds 594 plants, and 525 of them carry a rating taken from E271. The other 69 do not, and the difference matters if you are quoting them. Fifty-four come from the El Paso County CSU Extension list, which publishes a single deer-resistant category rather than a scale, mapped conservatively onto the second tier, and which records mule deer rather than white-tailed behaviour. Ten are food plot forage crops, where heavy browsing is the specification rather than a failure. Five rest on general horticultural consensus.

Across all 594 the split is 169 rarely damaged, 284 seldom severely damaged, 118 occasionally severely damaged and 23 frequently severely damaged. Counting only the 525 rated by Rutgers it is 169, 229, 113 and 14. Every plant in the rarely damaged tier is Rutgers-rated, and nine of the frequently damaged are forage crops sown to be eaten. Every plant page names the source it used. No plant is deer proof, and the source that produced those ratings says so itself. Methodology states which of our own fields are verified and which are not, and sources lists everything relied on.

Once you know the animal

Set expectations before spending. Minnesota Extension puts the benchmark for a repellent programme plainly: a 50 per cent reduction in deer browse is very successful, and 30 per cent is the likelier result. That number decides whether spraying is a strategy or a delaying tactic on the plant in question.

• Torn stubs up to six feet. Deer. How tall a fence needs to be if failure is unacceptable, or the egg-based repellent if it is not.
• Clean 45-degree cuts under two feet. Rabbits. Different fence, far cheaper.
• Tooth marks in bark, or plants lifting with no roots. Rodents. Pull mulch back from trunks. Nothing sprayed will reach them.
• Vertical shredding on a young trunk. Buck rub. Trunk guards before autumn.
• The same bed stripped every year. A planting problem rather than a protection problem. Garden design is the cheaper answer.

Keeping deer out of the garden is the sequence in full, in the order the decisions should actually be made: what to confirm, what to close, what to spray, and what to fence last. Its most useful section is the one on where deer get in, which is under the barrier and through the gate far more often than over the top. The deer FAQ answers the questions that come up next.

How to use the four guides below

Read them in the order the problem presents itself rather than top to bottom. If you are standing in the garden looking at a chewed plant, start with identifying the damage. If it turns out not to be deer, go to the other animals. If you already know it is deer and want the plan, start with keeping them out.

Judging the research is the odd one out and the one to read last, or on a different day. It will not save a hosta. It will tell you why two extension pages you trust disagree, and how much to move your own plan when a plant rated rarely damaged is being eaten in your garden anyway.