© Shutterstock

Vulnerability -

Keeping doors locked and windows closed is a must, but if you live in a house, chances are one or more of the windows are vulnerable.

© Shutterstock

No physical barrier -

This is mostly because there is nothing stopping a burglar from reaching your window. A dense spiky shrub, for instance, would probably make a robber think twice. Let's look at the best options in the following images.

© Shutterstock

Agave -

You might know agave best for being the tequila plant, but it can help keep your house secure, too. Agave's thick, spiny leaves and tips can grow real tall and inflict some damage on anyone who tries to go over or through it.

© Shutterstock

Rose -

It turns out the band Poison were right all along. Indeed, every rose has its thorn! And what better way to keep your property looking and smelling marvelously while being secure at the same time?

© Shutterstock

California fuchsia -

These flowers hanging downwards resemble fuchsia, but this is actually another plant. The stems are covered in spines, so placing them underneath windows might deter burglars from trying their luck.

© Shutterstock

Blackthorn -

If you have ever collected these small dark berries, called sloes, you know how painful their large spikes can be. They're easy to maintain and can grow up to 10 ft (3 m) tall, making a perfect natural barrier.

© Shutterstock

Cholla cactus -

These cacti, also known as "desert woodrats," can be great to help keep unwanted visitors off your property with their fur-looking barbed spines.

© Shutterstock

Barrel cactus -

Cacti are probably the first plants that come to mind when we think defense. This one in particular, also known as "mother-in-law’s seat," is especially nasty. Would you touch one?

© Shutterstock

Giant rhubarb -

These massive leaves can grow up to 6 ft (1.8 m) wide. The underside of the leaves have prickles, and its sap can cause skin irritations.

© Shutterstock

Acacia -

You might recognize acacia trees from Australia and Africa. The tree limbs have some serious spikes, capable of ripping off clothes and can easily pierce skin.

© Shutterstock

Prickly pear -

Its fruit, also known as "nopal" or "tuna fruit," have tiny hair-like spines called glochids that resemble fur. They can make a pretty much impenetrable barrier.

© Shutterstock

Porcupine tomato -

This evergreen shrub, native to Madagascar, might be very attractive with its beautiful flowers, but its natural spiky armor is not to be messed with.

© Shutterstock

Barberry -

Easy to grow and maintain in a variety of conditions, these can create a great spiky and dense barrier that will likely put off any potential burglars.

© Shutterstock

Oregon grape -

The Oregon grape holly or hollyleaved barberry is actually not even a grape! Thorn branches and leaves with sharp spines make it a good option as well.

© Shutterstock

Ocotillo -

You might associate these with the desert, but they can also live in other sun-filled dry areas. Their spiky canes make this plant pretty dangerous to touch.

© Shutterstock

Mesquite -

Also known as the "devil tree" in the US, its thorns are strong enough to pierce a car's tires! The species can be invasive, but it sure provides your home with very effective natural protection.

© Shutterstock

Japanese quince -

Offering pink, red, or white blooms, as well as edible fruit, the Japanese quince offers plenty of thorns, too.

© Shutterstock

Honey locust -

How gnarly do these protruding thorns look? Yes, they can really hurt someone, including the bad guys trying to rob your house.

© Shutterstock

Hawthorn -

You can find these in Europe, Asia, and North America. Their flowers are beautiful and their berries are edible, but this plant is also spiky, making it a great option for your front or back yard.

© Shutterstock

Hardy orange -

This relative of the citrus orange is native to China. Yes, it is edible, but it's very sour, so you might just use the tree because of its nasty thorns.

© Shutterstock

Devil’s walking stick -

This plant, also known as "Hercules club" and "prickly ash," has some seriously spiky prickles! If you have a large property, plant further away from your house, as it might spread.

© Shutterstock

Crown of thorns -

The name says it all. Just look at those thorns! But it's not just thorns—you'll also have beautiful flowers to adorn your outdoor area. Just make sure you wear protective gear when handling these.

© Shutterstock

Common holly -

You probably recognize these from Christmas decorations. Holly can create a pretty much impenetrable barrier too, though. Plus, it grows fast and it's easy to maintain.

© Shutterstock

Bougainvillea -

This beautiful colorful shrub hides a dark secret: dense branches with sharp thorns. It's more suitable for tropical climates and needs plenty of sunshine.

© Shutterstock

Blackberry -

Blackberries are lovely. Its spiky canes, not so much! These grow rapidly and easily, though, with some of them requiring a lot of pruning.

© Shutterstock

Pyracantha -

Also known as "firethorn," this shrub will give you beautiful flowers and edible berries, as well as offer you home protection with its thorns.

© Shutterstock

Chinese jujube -

This tree provides a fruit called "Chinese dates" or "Chinese pear." Young stems are particularly spiky!

Sources: (Gardener's Path) (Popular Mechanics)

See also: Inside the world's deadliest garden

© Shutterstock