Your landscape can be beautiful, your landscape can feed you, but your landscape can also protect you. Much like a well trained dog can be both a friend and a security system, your yard and garden can serve double duty too.
First Do No Harm
The first step to deterring burglars and other miscreants with your landscaping is to make sure you’re not doing anything to encourage them. Large shrubs or bushes that hide your windows or doors, allowing a burglar to work on them out of view, are a big no-no.
You should also keep a well maintained yard, believe it or not, a well maintained yard is a deterrent, criminals see a well maintained yard and think that you obviously take pride in ownership and are more likely to have well constructed locks or other security devices.
Fencing your yard is also a good idea, however make sure you’re not giving any bad guys a boost. So you have a 6 ft fence surrounding your back yard, do you have a grill, trash can, or raised planter right by the fence providing the would be interloper a leg up? If so, move it. Otherwise you’re doing the equivalent of leaving a ladder propped up against your house under a window (also, never leave ladders out, that is just asking for trouble).
So clean your yard, don’t give thiefs concealment, and don’t leave any tools out they might be able to use to climb in or over your defenses.
When you’re running from a bear…
Old story, when running from a bear, you don’t have to be faster than the bear, you just have to be faster than the other people you’re with. There is absolutely nothing your landscaping alone can do if a person is determined to break into your house, your goal is to make your house less attractive as a crime of opportunity than your neighbor.
The best way to do this, is with thorns. Now above I said you don’t want high bushes up near your windows and doors, and that is true, but lower bushes, especially thorny ones, are a good idea. You can build a hedge 5 or so feet off the walls of your house or your windows, not tall enough to hide the windows, but tall enough that you cannot step over it. You can also plant low bushes right up against your house near your windows, just keep them pruned so they don’t get too high, and really plant them right up against the house so there is no room to wiggle between the thorns and the siding.
Roses are an excellent choice, with pruning they stay open and won’t hide anything, their canes get decently thick and are not easily bent out of the way, and the thorns can be really, really, wicked. Some rose varieties are bread to have minimal thorns, but there are some varieties that are covered in huge thorns, to the point where you can’t even see the canes.
A plant I like and have blogged about before is barberry. I actually use both barberry and roses in my landscape for security purposes. Barberry is not as stiff as a rose would be, but it grows very very very bushy, and the thorns, while not as strong, do definitely hurt. They’re not as visible though, so might not deter someone until they are felt. If you could grow a barberry hedge around and under your windows, no burglar is going to want to wade through it to try to pry that window open. The plants are also very attractive.
Blackberry or boysenberry thorns I find to be particularly insidious, way stronger than raspberry thorns. Of course there are thornless varieties, so make sure you aren’t buy them, they also need supports so they don’t grow too low to the ground. But with these you can have your security and eat it too. Because they spread rapidly if there is say a short strip of land between your house and a walkway, that is actually a really good place to grow such bramble berries because they’re kept contained by your house on one side and the walkway on the other.
There are many woody shrubs or small trees that have wicked thorns, usually “thorn” is in the name. Such as blackthorn (Europe, originally), spiny hackberry (Texas), and my favorite, Hawthorn (Crataegus), native all over in the northern hemisphere, with hard sharp thorns up to 4 inches long. In Old English “haw” meant hedge, so you can see this plant has been used for protection for a long time. It can grow as a shrub or small tree, and can be pruned into a hedge (wear leather, please). It is also largely edible, the fruits and leaves can both be eaten (maybe that’s why the tree evolved such elaborate defenses). Hawthorn is one of those plants you could use as a very effective living fence if you have the time to let to grow and the time to maintain the pruning.