When we think of home security systems, we usually picture burglar alarms, 24-hour surveillance cameras and motion sensing lights. But long before the days of electronic security systems, plants and shrubbery were strategically planted and used as deterrents – to great effect!
An effective barrier against intruders, a thorny plant, bush or shrub will make it much harder for an intruder to get in undetected. They’re a fraction of the price of a state-of-the-art security system, and you’ll have a beautiful garden to show for it!
While shrubs and hedges often have spiky foliage that will add an extra layer of security to the perimeter of your garden, sharp succulents and houseplants can be placed on windowsills to make sneaking through a window that much harder.
Thinking of adding some thorny plants to your home or garden? Take a look at the best 25 spiky plants, hedges and bushes for added home security.
1. Agave
Native to Northern Mexico, Agave is a spiky succulent plant, with the Blue variety best known for being the primary ingredient in, you guessed it, tequila! But the variation we’re interested in is the Agave Americana, which can be grown in the UK.
This succulent can grow up to 2 m high with a 3 m spread. The leaves are stiff and dangerously pointed, so should give an intruder who makes contact with them a sharp shock!
Agave plants prefer a full sun position and well-drained soil. Provided they are protected from excessive rainfall in the winter, they should be able to cope with cold and frost. Many people choose to grow agave in their container garden, moving them inside in late summer.
2. Hawthorn
Known for its pretty pale-pink blossoms and sharp thorns, Hawthorn makes an attractive perimeter hedge. This hedge is the epitome of ‘look but don’t touch’. The thorns are seriously sharp and up to 3 cm long. Hawthorn is a great intruder deterrent, but the pretty blossoms ensure there’s no compromises to be made when it comes to appearance!
Hawthorn is fast growing – up to 60 cm a year. It grows well in any soil type.
3. Firethorn
Firethorn or Pyracantha is a tough, evergreen shrub from the Rose family. This shrub is often mistaken for thorn, but the two are actually distinct.
Firethorn can be grown as a freestanding shrub or trained to grow against an existing garden wall. In the spring, it’ll produce beautiful white blossoms, while you’ll also see bright red berries in the summer months.
This shrub is a fantastic natural barrier. If you’ve ever been pricked by one of these thorns, you’ll understand why!
4. Holly
This thick, evergreen hedge doesn’t need much introduction. Native to the UK and Europe, Holly bushes are known for their attractive, evergreen foliage and glossy but seriously spiky leaves.
The holly plant provides a great nesting site for a variety of wildlife, as the spiky leaves can deter predators, as well as human intruders!
5. Red Barberry
Barberry is a great choice if you’re after a deterrent against intruders that doubles up as a privacy screen. It has sharp thorns that keen intruders at bay, and striking purple leaves.
Its low maintenance requirements means this is a great choice for most gardens. It requires well drained soil and a spot in full sun to partial shade. In the spring, Red Barberry produces pretty yellow flowers that should attract pollinators to your garden.
6. Blackthorn
This fast-growing plant can increase in size by up to 60 cm a year! It’s known for its blue sloes, white spring flowers and thorny stems that you really don’t want to get near to!
Ideal as an intruder deterrent or just a pretty hedge, Blackthorn is happy in most soils other than very waterlogged soil. Once settled, it requires virtually no care, although it should be cut back in the winter months.
7. Rose Bushes
Not only do rose bushes look beautiful, they can also keep intruders at bay! Getting pricked by one rose thorn is unpleasant enough, let alone landing in an entire bush!
There’s not many intruders who will voluntarily climb over a rose bush to get into someone’s garden. They are sharp and dense, with little gaps between the thorns.
If you’re worried about someone climbing over your fence, plant climbing roses for an extra layer of security.
8. Mahonia
This winter-flowering, evergreen shrub is usually planted on garden perimeters. The spiky thorns make it a great deterrent against intruders.
With bright yellow flowers that bloom in the winter, this shrub can be used to add some colour to your garden when the rest of it has died back. It looks great in borders mixed with other evergreen shrubs, and is tolerant of most conditions.
9. Gorse
Common gorse is a large, evergreen shrub covered in needle-like leaves and coconut scented yellow flowers. It’s found in western areas of the UK.
With prickly leaves and a robust growth character, this bush is perfect for exposed areas. Having said that, it spreads quickly and can become invasive, so knowledge of gorse control is required.
10. Berberis
The unique appearance of Berberis makes it a great choice for those who want to add something a little different to their garden. The thorny branches will deter intruders, while the red-purple foliage turns a fiery orange in the winter!
Berberis grows quickly – around 60 cm a year.
11. Blackberry
Blackberries are one of the few fruits that do well grown in shady conditions. For this reason, blackberry bushes are a great choice for North facing gardens or those that don’t get a lot of sun.
Blackberry bushes make a great deterrent against intruders thanks to their thorns, while the delicious fruit can be used to make crumbles and jams. It’s important to keep in mind that a single plant can spread 4 m or more when fully grown.
12. Euphorbia
A succulent native to West Africa, the Euphorbia is best known for its thick stems and spines. It’s often used as a houseplant, and should produce tiny flowers throughout the year.
If you’re after a small spiky plant to pop on your windowsill, this is a great choice. While it may not have the same impact as a thorny hedge outside, it’ll make it harder for an intruder to get in and out of your window quietly.
13. Giant Rhubarb
This robust perennial has been listed by the Metropolitan Police as one of the best plants for protecting your property from intruders – so it’s well deserving of its spot on this list!
Giant rhubarb is native to South America and can grow up to 2 m high. The leathery leaves have sharp spikes on the back and along the stems – thorny enough to send any burglar running!
14. Prickly Pear
With a name like ‘Prickly Pear’, it’s no surprise this cactus has made our list! The Prickly Pear cactus has stems which resemble a pair of (albeit very spiky) rabbit’s ears! This cactus likes to be grown in a warm, bright spot and it needs to be kept above 10°C in the winter.
Although it won’t survive a winter frost, this cactus can be moved outside in the warmer weather to protect vulnerable corners of your garden or gaps in your fencing.
15. Golden Barrel Cactus
Another cactus that makes the list is the Golden Barrel cactus
This slow-growing cactus has barrel-shaped stems and can live up to 30 years. It needs to be grown inside so won’t protect the outside of your garden, but placing this pumpkin-shaped cactus on your windowsill will give anyone who dares to enter a spiky shock! Those ferocious, tiny spikes need to be taken seriously.
16. California Fuchsia
Looking stunning in almost any garden, courtyard or coastal, formal or informal, it’s well worth adding California Fuchsia to your outdoor space. This semi-evergreen shrub has spiky flowers that bloom all spring and summer.
It’s native to dry climates and requires lots of sunlight.
17. Devil’s Walking Stick
Characterised by the sharp spines found on the leaf stalks, stems and branches, this interestingly-named shrub grows best in full sun or partial shade.
It can tolerate a range of soils and doesn’t need much water. Reaching a height of over 30 ft, this shrub does require a little maintenance!
18. Aloe Vera
Everyone’s favourite spiky plant, aloe vera plants are best known for their medicinal properties. The aloe vera plant has serrated leaves which means it can be placed on a windowsill to give any intruders a prickly greeting! Aloe vera plants like a bright, sunny spot.
READ NEXT: 17 Plants That Look Like Aloe Vera
19. Chinese Jujube
Native to China, the Chinese Jujube is a tree that can reach up to 40 feet tall. It can be grown anywhere in the UK, and produces small fruits that taste like apples, until they dry out when the taste changes to that of dates!
The reason Chinese Jujube has made this list is because its leaves have sharp spines at their base. Planting this tree in a corner of your garden can deter thieves from climbing over your fence.
20. Snake Plant
Snake plants are an immensely popular houseplant thanks to their ease of care. Aptly otherwise known as Mother-in-law’s Tongue, Snake plants have ultra-sharp points at the tips of their leaves.
These low maintenance houseplants are perfect for entry level plant owners. They are an easy plant to care for, needing very little water, average temperatures and bright light.
21. Mountain Pine
This hardy little tree has long sharp needles that’ll add an extra layer of security to your garden. It provides year-round colour and structure to your outdoor space, while bringing some mountainous charm to UK gardens!
A Mountain pine tree grows best in full sun and well drained soil. It can grow up to 4 m tall, and looks stunning when positioned at the back of borders. The sharp needles mean no intruder will be able to use it as a prop to help them into your garden.
22. Creeping Juniper
This low growing shrub thrives in Britain’s wet conditions and is one of the hardiest shrubs around. Another listed by the Metropolitan police as a burglar preventing plant, this shrub has thorny stems and foliage. It can spread up to 4 m and needs very little pruning.
23. Smilax Aspera
Smilax Aspera, or prickly ivy, is an evergreen climber which can be trained to climb your garden fence. Once established, this climber forms a dense tangle of thorny stems and heart-shaped leaves that’ll make scaling a fence a whole lot more uncomfortable!
This plant prefers to be in full sun or partial shade, and does best in well-drained soil.
24. Aralia Elata
A large deciduous shrub or small tree, Aralia Elata has spiky stems and tiny cream flowers. This plant grows to a height of 12 m, and reaches a spread of 8 m. It prefers partial shade and a sheltered spot.
The viscous prickles of the Aralia Elata will provide your garden with extra security in the winter months.
25. Dragon Tree
The Dracaena Marginata or ‘Dragon Tree’ is an evergreen tree which can be grown indoors in the UK. It’s known for its distinctive spiky leaves and air purifying abilities, plus it makes an eye-catching addition to your home.
When grown indoors, Dragon Trees can grow up to 2 m tall. While the sword-like leaves are unlikely to deter committed thieves, this imposing houseplant will give any intruder a shock if they bump into it in the dark!