These 9 plants could double as security systems
For effective home security, get some plants with a little bit of attitude

Acacia, <i>Fabaceae</i>
Acacia, Fabaceae: Acacia trees are often associated with Australia, which makes sense—it takes a tough tree to survive in a tough land. But it's also native to Africa, and rumor has it that, in Egypt, the leaves were ground up and used to treat hemorrhoids.
But its the tree's limbs that hand out the most punishment. These barbarous branches are studded with curved prickles that excel at snagging and not letting go.

Blackberry, <i>Rosaceae</i>
Blackberry, Rosaceae: Think of this plant like no nonsense rose, with no showy flowers and all canes and prickles. They're incredibly fast-growers, and can quickly morph into a twisted wall of pain reaching 5-feet-high, and as wide as you'd like. Because of their tendency to grow quickly, you'll need to be a diligent pruner, but hey, at least you get those berries.

Bougainvillea, <i>Nyctaginaceae</i>
Bougainvillea, Nyctaginaceae: A fast-growing shrubby vine that can grow 40-feet-long, Bougainvillea uses its thorny stems to support itself on nearby plants or structures. The colorful display is actually large, papery bracts that surround the tiny flowers, and you definitely don't want this plant's sap to touch your skin.

Crown of thorns, <i>Euphorbia</i>
Crown of Thorns, Euphorbia: Although a great name for any death metal album, this climbing shrub grows 3- to 5-feet-high and sends heavily armed branches in every direction. It usually needs support and looks for other plants or a fence to hold it up. Crimson summer flowers put a beautiful face in front of the insidious matrix of thorns beneath. Supposedly, A circle of Euphorbia was placed on Jesus' head to make the infamous "crown of thorns." And this plant is evil all the way through, as its sap will irritate skin and can be toxic if ever ingested. Though if you ever eat this thorny nightmare, you might experience some other problems as well.

Firethorn, <i>Pyracantha</i>
Firethorn, Pyracantha: Pyracantha is ready to do battle with just about anything you could throw at it, which includes pruning shears. It's armed with needle-sharp spikes every few inches along its stems and branches, and the final armaments are growing tips that are 4-inch-long hypodermics. It's common name, Firethorn, is no joke.
Pyracantha can grow 10-feet-high and nearly as wide. It's a hardy plant that endures plenty of abuse, and it can spread quickly. You'll need to be ready for battle if you hope to save your yard from this thorny beast.

Honey locust, <i>Gleditsia</i>
Honey Locust, Gleditsia: Nobody's climbing this tree, which can grow 60- to 90-feet-tall, because the rough bark of the honey locust is often covered with 6-inch dagger-like thorns—it's the Michael Myers of plants. Botanists say the thorns evolved to protect the tree from giant sloths and short-faced bears that roamed North America thousands of years ago. Although these pre-historic fauna are no longer around, the flora's deadly defense still are.

Oregon grape, <i>Mahonia</i>
Oregon grape, Mahonia: Mahonia may have bright evergreen leaves, but don't let that cheery foliage catch you unaware. Each waxy leaf is rimmed with Lilliputian spines that easily penetrate clothing, including leather. The shrub produces dense foliage that can be shaped into a hedge, but at least its clusters of edible blue-black berries are a late-season treat.

Porcupine tomato, <i>Solanum</i>
Porcupine tomato, Solanum: It'd be hard to find a more aggressive-looking combo of leaves and stems than Solanum, aka devil's thorn, a hardy shrub that can grow 5-feet-tall. Some species contain a toxic alkaloid that, if ingested, can cause serious sickness and even death. As if those spines weren't scary enough.

Rose, <i>Rosa</i>
Rose, Rosa: A rose by any other name would be just as ornery. Whatever type you grow—garden, climbing, ground cover—you'll get a beautiful flowering plant with unsurpassed irascibility. As you've likely experienced before, roses draw blood, and they enjoy it. Trail climbers over fences and add garden roses and ground cover to the sunny sides of the house.
Acacia, <i>Fabaceae</i>
Acacia, Fabaceae: Acacia trees are often associated with Australia, which makes sense—it takes a tough tree to survive in a tough land. But it's also native to Africa, and rumor has it that, in Egypt, the leaves were ground up and used to treat hemorrhoids.
But its the tree's limbs that hand out the most punishment. These barbarous branches are studded with curved prickles that excel at snagging and not letting go.
Blackberry, <i>Rosaceae</i>
Blackberry, Rosaceae: Think of this plant like no nonsense rose, with no showy flowers and all canes and prickles. They're incredibly fast-growers, and can quickly morph into a twisted wall of pain reaching 5-feet-high, and as wide as you'd like. Because of their tendency to grow quickly, you'll need to be a diligent pruner, but hey, at least you get those berries.
Bougainvillea, <i>Nyctaginaceae</i>
Bougainvillea, Nyctaginaceae: A fast-growing shrubby vine that can grow 40-feet-long, Bougainvillea uses its thorny stems to support itself on nearby plants or structures. The colorful display is actually large, papery bracts that surround the tiny flowers, and you definitely don't want this plant's sap to touch your skin.
Crown of thorns, <i>Euphorbia</i>
Crown of Thorns, Euphorbia: Although a great name for any death metal album, this climbing shrub grows 3- to 5-feet-high and sends heavily armed branches in every direction. It usually needs support and looks for other plants or a fence to hold it up. Crimson summer flowers put a beautiful face in front of the insidious matrix of thorns beneath. Supposedly, A circle of Euphorbia was placed on Jesus' head to make the infamous "crown of thorns." And this plant is evil all the way through, as its sap will irritate skin and can be toxic if ever ingested. Though if you ever eat this thorny nightmare, you might experience some other problems as well.
Firethorn, <i>Pyracantha</i>
Firethorn, Pyracantha: Pyracantha is ready to do battle with just about anything you could throw at it, which includes pruning shears. It's armed with needle-sharp spikes every few inches along its stems and branches, and the final armaments are growing tips that are 4-inch-long hypodermics. It's common name, Firethorn, is no joke.
Pyracantha can grow 10-feet-high and nearly as wide. It's a hardy plant that endures plenty of abuse, and it can spread quickly. You'll need to be ready for battle if you hope to save your yard from this thorny beast.
Honey locust, <i>Gleditsia</i>
Honey Locust, Gleditsia: Nobody's climbing this tree, which can grow 60- to 90-feet-tall, because the rough bark of the honey locust is often covered with 6-inch dagger-like thorns—it's the Michael Myers of plants. Botanists say the thorns evolved to protect the tree from giant sloths and short-faced bears that roamed North America thousands of years ago. Although these pre-historic fauna are no longer around, the flora's deadly defense still are.
Oregon grape, <i>Mahonia</i>
Oregon grape, Mahonia: Mahonia may have bright evergreen leaves, but don't let that cheery foliage catch you unaware. Each waxy leaf is rimmed with Lilliputian spines that easily penetrate clothing, including leather. The shrub produces dense foliage that can be shaped into a hedge, but at least its clusters of edible blue-black berries are a late-season treat.
Porcupine tomato, <i>Solanum</i>
Porcupine tomato, Solanum: It'd be hard to find a more aggressive-looking combo of leaves and stems than Solanum, aka devil's thorn, a hardy shrub that can grow 5-feet-tall. Some species contain a toxic alkaloid that, if ingested, can cause serious sickness and even death. As if those spines weren't scary enough.
Rose, <i>Rosa</i>
Rose, Rosa: A rose by any other name would be just as ornery. Whatever type you grow—garden, climbing, ground cover—you'll get a beautiful flowering plant with unsurpassed irascibility. As you've likely experienced before, roses draw blood, and they enjoy it. Trail climbers over fences and add garden roses and ground cover to the sunny sides of the house.
Acacia, <i>Fabaceae</i>
Acacia, Fabaceae: Acacia trees are often associated with Australia, which makes sense—it takes a tough tree to survive in a tough land. But it's also native to Africa, and rumor has it that, in Egypt, the leaves were ground up and used to treat hemorrhoids.
But its the tree's limbs that hand out the most punishment. These barbarous branches are studded with curved prickles that excel at snagging and not letting go.
Blackberry, <i>Rosaceae</i>
Blackberry, Rosaceae: Think of this plant like no nonsense rose, with no showy flowers and all canes and prickles. They're incredibly fast-growers, and can quickly morph into a twisted wall of pain reaching 5-feet-high, and as wide as you'd like. Because of their tendency to grow quickly, you'll need to be a diligent pruner, but hey, at least you get those berries.
Bougainvillea, <i>Nyctaginaceae</i>
Bougainvillea, Nyctaginaceae: A fast-growing shrubby vine that can grow 40-feet-long, Bougainvillea uses its thorny stems to support itself on nearby plants or structures. The colorful display is actually large, papery bracts that surround the tiny flowers, and you definitely don't want this plant's sap to touch your skin.
Crown of thorns, <i>Euphorbia</i>
Crown of Thorns, Euphorbia: Although a great name for any death metal album, this climbing shrub grows 3- to 5-feet-high and sends heavily armed branches in every direction. It usually needs support and looks for other plants or a fence to hold it up. Crimson summer flowers put a beautiful face in front of the insidious matrix of thorns beneath. Supposedly, A circle of Euphorbia was placed on Jesus' head to make the infamous "crown of thorns." And this plant is evil all the way through, as its sap will irritate skin and can be toxic if ever ingested. Though if you ever eat this thorny nightmare, you might experience some other problems as well.
Firethorn, <i>Pyracantha</i>
Firethorn, Pyracantha: Pyracantha is ready to do battle with just about anything you could throw at it, which includes pruning shears. It's armed with needle-sharp spikes every few inches along its stems and branches, and the final armaments are growing tips that are 4-inch-long hypodermics. It's common name, Firethorn, is no joke.
Pyracantha can grow 10-feet-high and nearly as wide. It's a hardy plant that endures plenty of abuse, and it can spread quickly. You'll need to be ready for battle if you hope to save your yard from this thorny beast.
Honey locust, <i>Gleditsia</i>
Honey Locust, Gleditsia: Nobody's climbing this tree, which can grow 60- to 90-feet-tall, because the rough bark of the honey locust is often covered with 6-inch dagger-like thorns—it's the Michael Myers of plants. Botanists say the thorns evolved to protect the tree from giant sloths and short-faced bears that roamed North America thousands of years ago. Although these pre-historic fauna are no longer around, the flora's deadly defense still are.
Oregon grape, <i>Mahonia</i>
Oregon grape, Mahonia: Mahonia may have bright evergreen leaves, but don't let that cheery foliage catch you unaware. Each waxy leaf is rimmed with Lilliputian spines that easily penetrate clothing, including leather. The shrub produces dense foliage that can be shaped into a hedge, but at least its clusters of edible blue-black berries are a late-season treat.
Porcupine tomato, <i>Solanum</i>
Porcupine tomato, Solanum: It'd be hard to find a more aggressive-looking combo of leaves and stems than Solanum, aka devil's thorn, a hardy shrub that can grow 5-feet-tall. Some species contain a toxic alkaloid that, if ingested, can cause serious sickness and even death. As if those spines weren't scary enough.
Rose, <i>Rosa</i>
Rose, Rosa: A rose by any other name would be just as ornery. Whatever type you grow—garden, climbing, ground cover—you'll get a beautiful flowering plant with unsurpassed irascibility. As you've likely experienced before, roses draw blood, and they enjoy it. Trail climbers over fences and add garden roses and ground cover to the sunny sides of the house.
For effective home security, get some plants with a little bit of attitude
Related Content
Plants have evolved all sorts of wickedly clever defense mechanisms, and the most primal—and effective—are thorns, prickles, and spines. Spiny plants can be a hassle when it comes to maintenance and pruning, but when it comes to your personal home security, these masters of pain kick serious butt defending property lines and first-floor windows.
As a bonus, most of the plants trick themselves out with delicate blossoms in spring and colorful berries in fall. They're tough and hardy across many growing zones, and those that are shrub-like can be pruned into impenetrable hedges. This helps keep any home from looking like a max security complex.
If you have kids or animals, these may not be the plants for you. But for many, it's a more elegant solution than an unsightly barbed wire fence.