Equipped with sharp weaponry beneath deceptively innocent flowers, plants with thorns have developed to discourage ravenous herbivores from nibbling on their yummy stems. However, their blade-studded structure might have an alternate purpose within your garden! That is, to jab any inquisitive onlookers and intruders seeking to unlawfully traverse your property. Any stranger looking for trouble? Get a prick! So, without further ado, get your protective gear on as we traverse through the thorns.
What Are the Thorn Types of Plants?
Although the terms describing pointy shrubs are interchangeably used in literature, there is a consensus. In short, "spinescent" or “thorny” plants are botanically classified based on the type of tissue in which they arise from:
- Thorns. This axillary protrusion arises from a plant's trunk or stem tissue. Various woody shrubs, including hawthorn and acacia, possess these trunk-borne pokes.
- Spines. Rather than forming a fully-fledged leaf, plants produce pointed spines to defend themselves. Also called cladodes, most cacti bring forth this type of piercing outgrowth.
- Prickle. Thorny bushes that neither develop spikes from the stem nor leaf tissue are called prickles, described as corky appendages directly forming from dermal tissue. The next time you say “This rose has thorns”, consider it's actually… Prickles. The rose has prickles.
- Spinose Leaf. Other plants simply prefer to handle a bloody defense with the means of their foliage. The "teeth" or dentations of holly serve as a great example.
So many types of thorns! Nature sure knows how to protect its beauty.
What Is the Purpose of the Thorn Plants?
Driven by the pressure to survive hungry grazing animals, plants with thorns have surpassed natural selection by modifying their morphology. In simple terms, prickly plants are likely to reach the reproductive stage and produce offspring because they effectively avoid being snacked on.
Can We Use Thorny Plants to Deter Trespassers?
You can absolutely prevent intruders by putting a barrier of prickly plants. It is not only animals that are deterred from eating a wall of thorny plants but also those unwelcome guests that may enter your garden! Barbed wire sure doesn't look half as pretty.
Big List of Plants with Thorns
Although multitudinous thorny species have been described, we have selected the most common and exotic, including thorn plant images with names, in the following list:
Thorny Bushes
Numerous types of thorny bushes have been used as landscape plants, and some possess intriguing qualities that will surely prompt you to own one!
With Pink Flowers
- Bougainvillea. A queen bee of flowering thorns, Bougainvillea definitely deserves attention for its versatility, variety of colors, and eccentric blooms. It is mainly grown as a balcony plant that blends perfectly with a whitewashed of ivory-hued Mediterranean houses.
- Rose. Talking about a plant with thorns or "prickles," who would ever forget roses? Call it classic, it's fantastic. From multi-petalled to a single-whorled corolla, no gardener can resist the appeal of this royal and proud flower! This regal beauty requires your attentive care: a sunny spot and regular pruning.
- Japanese Quince (Chaenomeles japonica). As the name implies, it is native to Japan and commonly seen producing spectacular pink flowers in spring. In summer, you can even get some edible fruits from this short shrub! For best results, plant in an open spot, water moderately, and shape the greenie's canopy while young.
- Mimosa borealis. A close relative to the family of beans, this medium-sized tree measuring 3-6 feet (1-2 m) is decorated with globular, bristled magenta flowers–a common sight in summer! Water it sparingly and plant in partial to full sun to avoid the consequences of possible rotting.
With White Flowers
- Natal Plum (Carissa macrocarpa). With their shooting clustered 6-petalled white flowers, natal plums are equally captivating visually and olfactory. Ah, their jasmine-reminiscent smell is simply irresistible! This tall, drought-tolerant flowering tree only requires little pruning and watering and is perfect in seaside gardens.
- Silverthorn (Elaeagnus pungens). Soaring up to 15 feet (5 m) in height, it is one of the white-flowering thorn bushes that literally thrives with neglect! It requires no fertilizer and minimal watering. Keep in mind that this green pet is considered invasive, so it is always worth checking whether it is banned in your region.
- Hawthorn (Crataegus spp.). Joining the league of petite shrubs is hawthorn! This plant is studded not only with thorns but also cherry blossom-esque white flowers. Like average landscape plants, this can also produce lush growth in typical garden soils and periodical watering.
- Honey Locust (Gleditsia spp.). Straight from the east-central US, Honey Locust is prized for its golden yellow leaves in autumn and striking pendulous white flowers in spring! If you ever decide to plant this tree, select a spacious spot for it to proliferate in a few years, reaching about 50 ft (15 m) high!
With Long Thorns
- Japanese Barberry (Berberis thunbergii). Be careful as you're passing by this 8 ft (3 m) thorny plant… Unless you want to deal with a bunch of over half an inch length (2 cm) looming spikes! We know the shrub looks innocent and cute, however, we assure you, Barberry's hidden arsenal is hiding straight underneath the rounded maroon leaves. This tough greenie can thrive in compact and friable soils, so it's probably in your garden to stay (and to sting).
- Blackthorn (Prunus spinosa). Now introducing a native of the woodlands of England! This spiny member of the plums, cherries, and peaches family is feared by the local fauna because of its narrow, right-angled 2-3 inches (6 cm) thorns. Grow the bush in moist, sandy soil under full or partial sun, and enjoy a plentiful harvest of berries!
- California cholla (Cylindropuntia californica). Arising from the 7-inch (18 cm) columnar stem, Cylindropuntia's terrifying inch-long (3 cm) cladophylls are absolutely uninviting to anyone daring to cross your garden border! This eccentric greenie is a preferred choice in desert-themed landscapes.
With Pointed Leaves
- Ilex aquifolium (Common Holly). “Holly moly!”, would, perhaps be the first (hopefully, not last) words of a trespasser bruised by Commn Holly's spinose leaves. Standing 10-12 ft (3-4 m) tall, this holiday shrub is not only a favorite Christmas decor but is also used as defense hedge to deter border-crossers! Holly can thrive without fertilization and can quickly spread in a few years time.
- Porcupine tomato (Solanum pyracanthos). Give some love to one of the few representatives of bushes with thorns that can be cultivated in warm zones beyond 9! Yes, we know it was a long introduction but having a tropical biome representative on the list is pretty huge, isn't it? Growing on seasonally arid tropical biomes of Madagascar, don’t get fooled by its captivating bright purple flowers as its leaves are studded with stabbing outgrowths adjacently arising from the surface.
- Agarita (Mahonia trifoliolata). Recognizable with its distinctly spear-sharp leaf lobes and aggregated amber flowers, Agarita is a useful hedgerow as much as an aesthetic flowering plant. It lives through warm zones from 7-9 with full or partial sunlight. For best results, plant in sandy, moist soils with at least 3 ft (1 m) distance.
- Oregon Grape (Mahonia aquifolium). Like the Common Holly, the evergreen 3-6 ft (1-2 m) tall Oregon grape has modified leaves with piercing serrations for herbivory defense. To balance its wickedness and beauty, it is blessed with a glorious cluster of yellow flowers. Furthermore, you don't have to worry about where to plant because it can thrive anywhere!
With rounded leaves
- Ocotillo (Fouquieria splendens). Surviving in the dry areas of North America, the Ocotillo plant stands out with its unique features. It has long, slender stems that can reach lengths of 20 to 30 feet (about 6 to 9 meters), covered in clusters of gray thorns that are around 1.5 inches (3 to 4 centimeters) long. Similar to other desert plants, it requires only a small amount of water to thrive, making it a great choice for creating a durable plant fence.
- Firethorn (Pyracantha coccinea). During the summer, this thorny bush becomes adorned with ruby or topaz-colored berries, adding a touch of sparkle. Firethorn holds high ornamental value due to its beautiful ivory-white flowers during spring and its slender, elongated leaves. To keep your greenie thriving, water it only when there's a drought and provide yearly fertilization to promote plentiful blooming and fruit production
- American Barberry (Berberis canadensis). Berberis is a compact shrub that reaches a height of approximately 6 feet (2 meters). It features clusters of three spikes adorned with rounded, serrated leaves. Berberis canadensis is actually closely related to the Japanese barberry and is a low-maintenance plant that requires minimal care. However, those of you residing on a wheat farm, stay away from this candidate! If you plant this shrub, it will become an alternate host for wheat rust.
- Alluaudia ascendens. Endemic to Madagascar, Alluaudia ascendens is a columniform succulent plant characterized by its circular or two-lobed leaves, spiky gray stem, and V-forming canopy. To raise this exotic species, plant in sandy or free-draining garden beds; avoid growing in crowded areas as it can easily rot with high humidity!
Trees
Apart from possessing sharp thorns, these sturdy plants have developed ingenious strategies to grow to impressive heights as a way to deter herbivores. Here are a few examples of greenies on the bigger side:
- Pink Silk-floss tree (Ceiba speciosa). It's impossible to ignore the splendid array of pink flowers that adorn the canopy of the pink silk-floss tree in midsummer. Its swollen trunk, adorned with razor-sharp thorns, stands as a defense against an extinct primeval group of mammals, especially the giant ground sloth. This tree is remarkably drought-tolerant and behaves like a desert plant, which means watering might not be necessary at all!
- Devil’s Walkingstick (Aralia spinosa). Located in the moist eastern woodlands of the US is the devil's walkingstick tree, potentially named for its menacing spines present on leaf stalks, stems, and branches. This plant demonstrates relative hardiness, enduring dry periods, urban pollutants, pests, and deer. Remember to eliminate the suckers to prevent unwelcome spreading in the wild.
- Sweet Acacia (Vachellia farnesiana). This greenie features yellow pom-pom flowers that bloom from May to October. With a maximum height of 15-25 feet (5-8 meters), this short tree exhibits zigzagging branches, each point adorned with inch-long (3 cm) thorns. If you're tending to a shaded garden, keep in mind that this might not be your best option; this plant thrives in sunny spots instead!
- Mesquite Tree (Prosopis spp.). A familiar presence in the arid regions of North America is the mesquite tree, a member of the legume family. This tree grows slowly but possesses strong resilience to drought, typically reaching an average height of 20 feet (6 meters), which makes it an effective natural barrier. If you decide to cultivate it in your garden, here's a free lifehack! Always remember to give the tree a generous sip during its initial establishment phase and then cut on watering.
Vines
"If you can't stand tall like a mighty tree, then at least cling to a standing one." This could very well be the motto of these trailing thorny species:
- Greenbiers (Smilax spp.). Comprising approximately 300 species, Greenbriers are recognized as proficient climbers. Their clinging appendages on their semi-woody stems and heart-shaped leaves facilitate this ability. While they create a jungle-like ambiance in your garden, remember to consistently trim the fast-growing vines. If left unchecked, they can encroach upon and compete with other plants.
- Wild Cucumber (Echinocystis lobata). True to its name, the Wild Cucumber is akin to the cucumbers you're familiar with; the only distinction lies in its spiky fruits that reach a diameter of 2 inches (5 cm)! While some gardeners embrace this trailing plant that can stretch up to 25 feet (8 meters), others deem it a weed.
- Multiflora Rose (R. multiflora). Although Multiflora Rose appears as a vine, it is, in fact, a perennial shrub that exhibits prolific growth. R. multiflora's rapid development has earned it appreciation among numerous gardeners and breeders. Nonetheless, due to these very traits, it has been designated as an invasive species in the US, as it has the tendency to overtake native flora through its sprawling growth.
- Climbing Rose hybrids (Rosa spp.). You can't go wrong if you opt for a Climbing Rose hybrid. The main challenge you might encounter is the abundance of colors, shapes, and petal layers available in the market. Similar to many other rose types, these hybrids thrive in sunny locations and benefit from consistent pruning to encourage flowering.
Other Thorny Plants
These rebel plants with thorns on their leaves and stems might defy the categories we talked about earlier, but they definitely deserve a shout-out for their charismatic appearance. Unique is often better!
Red Thorns
- Fuchsia-flowered Gooseberry (Ribes speciosum). Once the foliage bursts forth in spring, the fuchsia-flowered gooseberry will absolutely blow you away. Its blazing crimson blooms dance on branches adorned with fiery-red spines. To maximize the potential of this 5 ft (2 m) flowering shrub, go ahead and plant it wherever you fancy! It can handle shade, sunshine, and even drought like a champ!
- Chinese Quince (Chaenomeles speciosa). Displaying its 5-petaled red-pink flowers during spring, Chinese Quince's scarlet-tinged spines remain visible even when the branches go bare. With an average size of 5 ft (2 m), its magnificence can be thoroughly appreciated with minimal maintenance, as long as it's planted in a loamy or sandy soil.
- Blackberry. Decked out with short but feisty reddish claws, blackberry canes go all out, forming a practically impassable wired barrier as their 6-9 ft (2-3 m) stalks stretch and droop to the ground. And yes, you might get a few scratches and battle scars, but guess what? It's totally worth it for the sweet, juicy fruits you'll snag! To get the most out of this berry bonanza, go for hybrid varieties and plant them in beds that know how to hold onto moisture, all while soaking up the sunshine like champs.
Thorns on Leaves
- Giant rhubarb (Gunnera manicata). Meet the giant rhubarb, a member of the tropical and subtropical Gunnera family. But hold on, it's nothing like the rhubarb we're used to in the kitchen! Instead of rhubarb's familiar flowers, this one rocks conical branched panicles. And those massive umbrella-like leaves? Guess what's hiding underneath? Yup, sturdy but sneaky sharp spikes all over the stalk. If you've got a damp, boggy garden or an artificial pond, say hello to your perfect match.
- Agave americana. If you're aiming for a desert-inspired garden, Agave americana is your go-to buddy. This plant flaunts sizable, dented leaves that fit right in. But here's the cool part: once it hits its reproductive phase, brace yourself for an impressive 15-25 ft-tall (5-8 m) shoot that rockets up from its base. Thanks to its striking sword-like leaves, it even doubles as a solid fence for your garden, especially handy when water is in short supply!
- Candelabra Aloe (Aloe arborescens). Like Agave, this desert plant shares similar dagger-like foliage but is born in arborescent stems. At least 1-2 times a year, you will be greeted with a broom-sized orangy-red inflorescence. In order to thrive, plant in sunny borders and simply water it at least once a month, or rain has precipitated in a few weeks.
Thorns on Stems
- Saguaro (Carnegiea gigantea). You won't be able to miss this towering, tree-like cactus adorned with formidable thorns. Its massive size demands attention. Placing Saguaro on your fence is a smart move, as it's practically hassle-free when it comes to maintenance, except for a little extra watering in the initial weeks of getting settled.
- African Milk tree (Euphorbia trigona). Reaching an average height of 9 ft (3 m), the African milk tree stands out as a fantastic option for fencing your yard. Despite its cactus-like appearance, it actually belongs to a different family of succulents and broadleaf plants. If you're dealing with a shady garden, this species is a spot-on choice. To encourage branching and create a net-like barrier, give its tops a gentle pinch now and then.
- Crown of thorns (Euphorbia milii). Available in a wide array of colors, this biblically-associated thorny plant is easy to grow with occasional watering and full sunlight. It may be worrisome when it sheds leaves but don’t give up on it easily! It is a normal growth pattern when it experiences slight changes in its environment.
Poisonous
- Thorn Apple (Datura stramonium). Although related to tomatoes, this trumpet-flowered plant gives rise to a thorny fruit. Inside are toxic seeds containing tropane alkaloids, which attack the central nervous system and suppress involuntary muscle movements, such as those involved in digestion. The leaves, too, carry this compound, so beware! Hence, keep a distance and appreciate its beauty from afar.
- Stinging Nettles (Urtica dioica). As the name implies, you don’t want to grope a leaf or stems- no matter how fuzzy they look! In fact, they are studded with stinging micro-needles. With a cosmopolitan distribution, it is widely used in the textile and cosmetic industry, sometimes being considered a weed. However, it serves as an important nesting ground for larvae of local butterfly species, and can, if properly stripped of its needles, make a great tea or addition to salads.
- Gymnosporia buxifolia. A flora local to South Africa, this 30-ft (9 m) tree is characterized by its ellipsoid foliage and clustered white flowers. Although the plant is used to remedy diarrhea (and snakebites!), its piercing 4 inches long (10 cm) spines are reputed to be toxic and irritable to the skin.
Plants with Thorns Identification
Most thorn plants on our list have adapted to dry habitats. For this reason, we advise watering your plant sparingly after its establishment. Depending on the species, they may defoliate seasonally as a strategy to cope with their changing environment. Want more targeted plant care? Consider using the PlantIn Identification tool. Take a shot of your little plant, and it will identify the species from flower and leaf information like a botany pro… speaking of which, ask our seasoned plant geeks for advice tailored just to you! Snap a picture of your greenie and get real human responses in just a few hours.
The beauty of all these plants teaches us one lesson: If you maintain a respectful distance, you can always enjoy nature's gifts without getting hurt.
