Shelter · Home Security
Security landscaping. Low, open, and well kept.
The yard is the first layer anyone crosses. Keep it open to view, make the approach to windows uncomfortable, and take away the easy climbs, without turning the house into a hedge maze or a fire risk.
By Dan Whelan, founder of New World Survival
Researched from government agencies, university extension services, and other published sources. See our sources
The core idea
Plants can hide a house, or help watch it.
Police crime-prevention units teach landscaping through a framework called crime prevention through environmental design. Two of its ideas apply to every yard: natural surveillance, which means keeping sightlines open so people can see what happens at your doors and windows, and using planting to steer people toward the front entrance and away from everywhere else.1
The first idea matters most. In a survey of 422 incarcerated burglars, most said they weigh whether other people are close enough to see them.2 A yard that lets neighbors and passersby see your front door works on that question every hour of the day. A wall of overgrown shrubs works against it.
One honest caution before the details. The heights and plant advice below come from police guidance, not from controlled studies of landscaping. What research does support is the value of being seen, which is why open sightlines lead this guide and thorns come second.
Renters: the yard usually belongs to the landlord. You can still ask in writing for overgrown shrubs by doors and windows to be trimmed, keep your own ladders and tools locked up, and keep plants on a porch or balcony from blocking the view of your door.
The low-and-high rule
Keep shrubs low and canopies high.
The rule of thumb leaves an open band between waist height and head height, where you can see a person standing in your yard. Police departments use slightly different numbers. The ranges below cover them.
2 to 3 feet
Shrubs and ground cover
Saint Paul says 2 feet.3 Seattle police, the King County Sheriff's Office, and the Columbus Division of Police say 3.1,4,5 Hold the lower number near doors and windows, where a person crouching would otherwise be hidden.
6 to 8 feet
Lowest tree branches
Saint Paul and Seattle limb trees up to 6 feet.3,4 King County and Columbus use 8.5,1 Higher canopies keep the view open under the tree and keep light from street lamps and porch fixtures reaching the ground.
Below the sill
Plants under windows
The St. Joseph County Sheriff's Office in Michigan says to keep ground plants under windows lower than the window sill.6 You keep the view out, and nobody can stand behind a shrub while working at the glass.
See-through
Fences and boundaries
Columbus says fences should let people see in.1 King County does not recommend solid fences around a property, because they are easier to climb and give cover.5 Open metal or chain-link trades a little privacy for visibility.4
Defensive planting
Thorns where they help, and nowhere they hurt.
The King County Sheriff's Office recommends bushes with thorns or prickly leaves under ground-level windows and along fences and walls, to make access and climbing harder.5 The Columbus Division of Police gives the same advice, and specifies low bushes.1
Pick for mature height
Seattle police name holly, Oregon grape, rosebushes, and cacti as examples.4 Many of these grow tall. Read the mature height on the tag, and choose a variety that will stay under your sill with ordinary pruning. A thorny shrub that reaches the gutter is a hiding place with thorns.
Leave room to work
Plant far enough from the wall that you can still reach the window to clean it, change a screen, and check the lock. If you have to wrestle a rosebush every time you open the window, you will stop opening it, or stop pruning.
Ask what grows locally
What thrives, and what spreads where it should not, varies by region. Your county extension office can suggest low thorny shrubs suited to your climate that are not considered invasive where you live.
Keep escape windows clear. The National Fire Protection Association tells households to plan two ways out of each room, usually a door and a window, and to check that escape routes are clear and windows open easily. It warns that items blocking doors and windows could keep you from escaping a fire.7
A thorny shrub below a bedroom window is that kind of obstacle for anyone climbing out at night. Leave the escape windows in your family safety plan free of thorns, and put defensive planting under the windows nobody would use to get out.
In wildfire country
The first five feet stay clear.
If wildfires happen where you live, the thorny-shrub advice above changes. Fire safety outranks deterrence, and the two can work together.
Why the strip by the wall matters
The Insurance Institute for Business and Home Safety recommends creating and maintaining a noncombustible zone in the first 5 feet around a building, including under an attached deck. Wind-blown embers collect at the base of exterior walls, and anything there that ignites puts flame and heat right against the house.8
Oregon State University Extension advises keeping that zone free of plants whenever possible, and specifically avoiding vegetation under windows, by doors, and near vents and eaves.9 A burning shrub under a window is exactly what this guidance is written to prevent.
What to do instead
- Keep the 5-foot strip in gravel, pavers, or bare ground. It also leaves the base of every wall in plain view, which serves security too.
- Move defensive planting farther out, along fence lines and property edges, and ask your local fire agency or extension office which plants suit your area.
- Let window locks, window security upgrades, and motion lighting do the job thorns would have done.
For the full wildfire picture, start with Wildfire in Local Risks.
The landscaping matrix
Area by area, in order of priority.
Use this to plan a yard that keeps things visible, discourages access, and keeps safe routes open for your household and visitors. The priorities are a suggested planning order, not measured security ratings.
Front door and porch
HighGoal: anyone approaching the door can be seen.
Do: keep shrubs low and the entry open to view from the street, and keep plants clear of the porch light.1,5
Avoid: dense planting that could hide someone beside the door or block the light.
Ground-floor windows
HighGoal: nobody can work at a window unnoticed.
Do: keep plants below the sill, with low thorny shrubs where they fit and room left to maintain and open the window.5,6
Avoid: tall planting that gives cover, thorns under any escape window, and any shrubs here in wildfire country.7,9
Front yard and street edge
HighGoal: the house, the street, and the neighbors can see each other.
Do: favor low planting and see-through fencing where sightlines matter.1
Avoid: a continuous dense hedge or solid fence that screens the front of the house.5
Side passage and gate
HighGoal: no unnoticed route to the back of the house.
Do: keep the passage clear, light the approach, and fit a gate latch that cannot be unscrewed from outside.5
Avoid: hidden pockets beside the gate, or plants that block the view down the passage.
Trees near the house
HighGoal: no branch works as a ladder.
Do: trim limbs that reach a roof, an upper-story window, a balcony, or over a fence.4,5
Avoid: sturdy low branches beside upper windows. Hire an arborist for anything you cannot reach from the ground.
Trellises, sheds, and climbing plants
MediumGoal: no structure doubles as a step up.
Do: place trellises and sheds where they do not give a climb to an upper window or roof.10,1
Avoid: a sturdy trellis, shed, or stacked furniture directly below an accessible upper window.
Paths and the visitor approach
MediumGoal: visitors naturally head to the visible front door.
Do: define one clear route to the main entrance and keep the planting along it trimmed.1
Avoid: planting that obscures the route or creates a sheltered spot to wait out of view.
Lights and camera views
HighGoal: plants never stand between a light or camera and what it covers.
Do: prune back from fixtures and camera sightlines, and recheck each season as plants grow.5
Avoid: a new leaf canopy that quietly blinds a motion sensor or a doorbell camera by midsummer.
Gravel strips under selected windows
OptionalGoal: an approach you might hear.
Do: consider gravel where it suits access and upkeep. Some sheriff's offices suggest it for the noise underfoot.6
Avoid: treating gravel as an alarm, and large rocks near glass, which could be thrown through it.6,5 We found no study that tests gravel.
The whole property
OngoingGoal: the benefits last past the first summer.
Do: trim on a schedule, and lock ladders and tools away and out of view.4,10
Avoid: overgrowth that creeps back into cover, and a ladder left against the house after yard work.
How to apply it: start at the entries, then walk it after dark.
Do the high-priority areas first. Front door, ground-floor windows, the side passage, and any tree that reaches the roof. A pair of hedge shears and an afternoon cover most of it.
Walk the yard after dark. Look for spots where a person could stand unseen near a door or window, and for plants blocking a light. The checklist in Lighting and Visibility pairs well with this walk.
Plan for the plant at full size. A new shrub looks tidy on planting day. Check its mature height and spread against the 2 to 3 foot rule and the sill line before it goes in the ground.
Put privacy where it does not hide an approach. A screen around a patio or hot tub is fine. A screen along the front walk or under the bedroom windows is not.
Treat landscaping as a supporting layer. It works alongside locked doors, secure windows, and good lighting, never in place of them. See The Layers of Home Security for how they fit together.
Common mistakes
Five ways a yard works against you.
Letting the thorny hedge grow tall
Defensive planting only works low. Once it rises above the sill it hides the window it was meant to protect.
Planting thorns under an escape window
The window your household plans to climb out of during a fire should open onto a clear path.7 Choose soft, low planting there, or none.
Copying the thorn advice in wildfire country
The first 5 feet around the house should hold nothing that burns, and windows are among the most vulnerable spots.8,9 Defensive planting moves out to the fence line.
Solving privacy with a solid front fence
It blocks the neighbors' view of your door along with the street's, and it is easier to climb and hide behind than open fencing.5
Leaving the tools that open the house in the yard
A ladder against the wall, a shovel by the back door, loose landscape rocks near a window. Seattle police advise keeping tools and ladders locked and out of view.4
Related guides
The yard is the outer layer.
Landscaping is part of the first layer of home security, perimeter and visibility. These guides cover what comes next.
How Burglars Choose a House
The three questions a burglar asks from the curb, and the 30-second walk that answers them.
The Layers of Home Security
Landscaping sits in Layer 1, perimeter and visibility. See all seven layers.
Lighting and Visibility
Motion sensors, lumen ranges, and placement. Pruned plants and good lighting work together.
Window Security
Locks, pins, film, and sensors. The layer that matters most where thorns cannot go.
Common questions
The questions that come up most.
How tall should shrubs be for home security?
Police crime-prevention guides put the limit between 2 and 3 feet. Saint Paul uses 2 feet; the Seattle Police Department, the King County Sheriff's Office, and the Columbus Division of Police use 3 feet. Under windows, keep plants below the window sill. Tree canopies should start 6 to 8 feet off the ground so the view under them stays open.
Should I plant thorny bushes under my windows?
Low thorny shrubs under ground-level windows are standard police advice, from Columbus, Ohio to King County, Washington. Keep them below the sill, leave room to open and maintain the window, and skip them under any window your household would use to escape a fire. In wildfire-prone areas, the Insurance Institute for Business and Home Safety recommends a noncombustible zone in the first 5 feet around the house, so put defensive planting farther out instead.
Does gravel under windows deter burglars?
Some police guides suggest it, including the St. Joseph County Sheriff's Office in Michigan, on the idea that footsteps on gravel are noisy. We found no study that tests it. Treat gravel as an optional extra, never a substitute for locked, secure windows, and use small gravel rather than large rocks that could be thrown through glass.
Continue reading
What’s next
Local Risks
Wildfire Home Preparation
Defensible space zones, ember-resistant vents and roofs, and how to ready the house and yard before fire season.
Help
Wildfire: What to Do Right Now
For when a fire is near: alerts, leaving early, and what to do with the house on the way out.
Home Security
Lighting and Visibility
Motion sensors, lumen ranges, and placement. Pruned plants and good lighting work together.