15 Most Common Weeds With Thorns

Weeds are unwanted plants that infiltrate gardens, lawns, and fields. These intruders compete with desired plants for vital resources like space, water, nutrients, and sunlight.

Beyond these challenges, some weeds stand out due to their thorns and spines, which can cause harm to both humans and animals. These thorny weeds not only pose risks of injury and irritation but also make the task of weed control more challenging.

In this article, we will dive into the realm of the most common weeds with thorns, shedding light on the unique issues they present and what is the best way to control them.

What Weeds Have Thorns?

There are many types of weeds that have thorns, spines, or prickles. Some are native to specific regions, while others are invasive species that have spread to new areas.

Thorns are sharp, woody projections that grow from the stems, branches, or leaves of some plants. They are altered branches that serve as a defense mechanism against herbivores.

Spines are also sharp structures that grow from plants, but they are altered leaves, stipules, or parts of the leaf. Prickles are similar to spines, but they are not part of the plant tissue. They are part of the plant outgrowths of the epidermis or bark.

Some have thorns all over their stems and leaves, while others have thorns only at certain parts of the plant. Some of them have large and conspicuous thorns, while others have small and hidden ones.

Now, let us get into the list of most common weeds with thorns.

Common Types Of Weeds With Thorns

Encountering thorny weeds in your garden or lawn is a familiar experience. Here, we highlight a selection of the most common weeds with thorns you might come across:

So, let’s dive in and discuss each weed with thorns in more detail.

Thistle

Thistle is a general name for several species of plants in the Asteraceae family that have spiny leaves and stems. Their seeds, dispersed by wind or animals, contribute to their widespread growth. While thistles can thrive across diverse environments, they particularly favor sunny places and fertile soils.

Thistles are notorious for their sharp spines and often have vibrant purple flowers. These weeds can quickly take over your garden if left unchecked. [1]

Blackberry

Blackberry refers to different kinds of shrubs or vines in the rose family (Rosaceae) that give rise to tasty black fruits. These plants have thorny stems and leaves, along with white or pink flowers. They are adaptable and can thrive in various places, but they love sunny spots with plenty of moisture.

While the reward of those delicious berries is sweet, handling blackberry bushes can be a bit of a hassle. They come equipped with thorns that can make your gardening experience a prickly affair. Regular maintenance is critical to keep these plants in check and ensure they don’t overrun your space. [2]

Pro Tip: When trimming a blackberry bush, remember that for every branch you snip, two more will sprout from the end of the cut. It’s a bit like the mythic hydra. Cut one, and more appear.

Bull Thistle

Bull thistles, formidable biennial weeds characterized by their imposing presence and distinctive large purple flowers, can become quite the eyesore in any garden or landscape. With their spiny stems and leaves, bull thistles command attention, but not in a favorable way. These thistles often take advantage of disturbed soil, establishing their dominance in any garden.

Their remarkable size and robust structure make bull thistles hard to miss. Their spines, almost resembling nature’s armor and serve as a warning to anyone who dares to come too close. Unfortunately, their rapid growth and invasive tendencies can turn even a well-kept garden into a battleground. [3], [4]

Removing bull thistles requires a determined approach. Simply cutting them down won’t suffice, as their tenacious root systems ensure their return. Instead, use a sturdy shovel and remove the entire root system, preventing any chance of regrowth.

Spiny Sowthistle

Spiny sowthistle is an annual weed that belongs to the aster family. It has spiny leaves and stems and bright yellow flowers that resemble dandelions. This weed can grow up to 5 feet (1.5 meters) tall and prefers moist and fertile soils.

Spiny sowthistles reproduce by seeds, which are produced in large numbers and have a white tuft of hairs that allow them to be carried by the wind far, far away. The seeds can remain viable in the soil for several years, making them difficult to eradicate. Spiny sowthistle can also regenerate from root fragments if the plant is cut or damaged.

Spiny sowthistle can be a nuisance in gardens, lawns, pastures, and crops, as it competes with desirable plants for space, water, and nutrients. It can also host several pests and diseases that affect other plants. [5]

Horsenettle

Horsenettle is a perennial weed that belongs to the nightshade family. It has spiny stems and leaves covered with fine hairs and white or purple flowers with yellow centers. It produces fruits that resemble small tomatoes, but they are poisonous to eat. The fruits contain solanine, a chemical that can cause nausea, vomiting, diarrhea, and headache.

Horsenettle can grow up to 3 feet (1 meter) tall and prefers sunny and dry habitats. It can tolerate drought, frost, and poor soils. This weed spreads by seeds and by underground rhizomes, which can form dense patches that crowd out other plants.

Horsenettle can be a problem in gardens, lawns, pastures, and crops, as it competes with desirable plants for resources and reduces the quality of crops. It can also pose a health risk to pets and livestock if ingested. Horses, cattle, sheep, and goats are especially susceptible to horsenettle poisoning. [6], [7]

Spiny Pigweed

Spiny pigweed is an annual weed that belongs to the Amaranthus family. It has spiny stems and leaves that are oval or lance-shaped. Also, this weed has green or red flowers that form dense spikes at the top of the plant or in the leaf axils. It produces small, black seeds that are edible and nutritious. Still, they can also be a nuisance in crops as they contaminate the harvest and reduce the yield. [8]

Spiny pigweed can grow up to 5 feet (1.5 meters) tall and adapt to various soils and environmental conditions. It can tolerate drought, salinity, and flooding. It spreads by seeds, which can remain viable in the soil for several years. Spiny pigweed can produce up to 100,000 seeds per plant, which can be dispersed by wind, water, animals, or human activities.

Spiny pigweed poses challenges in gardens, lawns, pastures, and crops by competing with wanted plants for vital resources like space, light, water, and nutrients. [9]

Burdock

Burdock is a common name for several species of biennial weeds that belong to the genus Arctium. They have large leaves shaped like hearts or ovals and purple flowers that form round heads at the end of the stems. They produce burs that are covered with hooks and cling to animal fur or human clothing. These burs contain seeds.

Burdock can grow up to 9 feet (2.7 meters) tall and prefers moist and rich soils. It can tolerate shade but needs full sun for flowering. This weed is often found in disturbed areas, such as roadsides, fields, pastures, and gardens.

Burdock can be a nuisance in gardens and lawns, as it competes with desirable plants for resources and space. It can also cause skin irritation and allergic reactions in some people and animals. The burs can be challenging to remove from clothing and can damage wool and other fabrics. [10]

Sandbur

Sandbur is a common name for several species of annual weeds that belong to the genus Cenchrus. They have grass-like leaves and usually green stems and green or brown flowers that form spikelets along the stems. They produce burs covered with spines and stick to human clothing and animal fur.

Sandbur is native to warm regions of the world but is now found in cooler areas as well. They can grow up to 1.5 ft (46 cm) tall and prefer sandy and dry soils. They can tolerate drought, salinity, and low fertility. These weeds are spread by seeds located in burs and can be dispersed by wind, animals, or human activities.

Prickly Lettuce

Prickly lettuce, also known as wild lettuce or compass plant, is an annual or biennial weed that belongs to the aster family. It grows 12 to 40 inches (0.3 to 1 meter) tall. It has narrow and lobed leaves with spines on the margins (the boundary area along the edge of the leaf) and midribs (the central vein or ridge of a leaf).

The lower leaves are larger and more lobed than the upper ones. The leaves tend to orient themselves north and south, giving the plant its common name of compass plant.

Prickly lettuce produces yellow flowers, somewhat similar to dandelions. The flowers are arranged in loose clusters at the end of the branches. The flowers are followed by small, brown seeds with a white tuft of hairs that allow them to be carried by the wind. The seeds can remain viable in the soil for several years, making them difficult to eradicate. [11]

Prickly lettuce is the ancestor of cultivated lettuce, but it is bitter and less palatable. It can grow in various habitats, such as roadsides, fields, pastures, gardens, and waste areas. This weed can tolerate drought, frost, and poor soils. It competes with desirable plants for resources and space. This will reduce the quality and quantity of desired crops.

Catchweed Bedstraw

Catchweed bedstraw, also known as cleavers or stickyweed, is an annual weed that belongs to the same family as coffee. It grows up to 6 feet (1.8 meters) tall and has square stems with tiny hooks that can cling to other plants, animals, or clothing. Catchweed bedstraw is a creeping plant that grows along the ground. It can only grow tall if it attaches to other high-growing plants, using its tiny hooks to cling to them.

This weed has whorled leaves with tiny hooks on the margins that are lance-shaped or elliptical and small white flowers in clusters. The flowers are followed by a seed shell that has hooks. These hooks help the plant to disperse its seeds by clinging to animal fur or human clothing.

Catchweed can grow in a wide range of habitats, such as fields, forests, gardens, and waste areas. It also can tolerate shady, moist, and low-fertility soil.

Catchweed bedstraw can be a nuisance in gardens and lawns as it competes with desirable plants. It can also create an untidy appearance by becoming tangled in other plants and forming mats on the ground.

Spiny Cocklebur

Spiny cocklebur, also known as prickly burweed or Bathurst burr, is an annual weed that belongs to the daisy family (Asteraceae). It grows up to 4 feet (1.2 meters) tall and has stems with long, sharp, yellowish spines at the leaf bases.

This weed has lance-shaped or elliptical leaves with tiny hooks on the margins and small white flowers in clusters. The flowers are followed by spiny burs that contain the seeds. The burs have two horns covered with hooked spines that can attach to animal fur or human clothing.

Spiny cocklebur can grow in various habitats, such as croplands, pastures, gardens, and waste areas. It prefers sunny, moist, and fertile soils. In addition, it can also tolerate saline and alkaline conditions.

Spiny cocklebur can reduce crop yields and quality by competing with desirable plants. It can also injure livestock and humans with its spines and burs. The plant and the burs can contain toxic substances that can be fatal to animals.

Jimsonweed

Jimsonweed is a poisonous weed that belongs to the nightshade family. It has large, toothed leaves and green or purple stems. It also has a strong and unpleasant smell.

This weed grows white or purple flowers that look like trumpets. After the flowers are pollinated, they turn into round or oval capsules with spines. The capsules are green at first, but they become brown when dry and ready to release many black seeds.

Jimsonweed can grow in many places, such as fields, pastures, gardens, and waste areas. It does not need much water, warmth, or good soil.

Jimsonweed is very dangerous to pets and humans if they eat any part of it. The plant has chemicals called alkaloids that can affect the brain and the heart. If someone eats jimsonweed, they may have symptoms like dry mouth, dilated pupils, blurred vision, confusion, agitation, hallucinations, or convulsions. They may also die from jimsonweed poisoning. [12]

Goathead

Goathead, also known as puncturevine, caltrop, or devil’s thorn, is an annual weed that belongs to the zygophyllaceae family. It has pinnate leaves with small leaflets and yellow flowers with five petals. It produces fruits segmented into five parts, each with two sharp spines. The fruits are hard and spiny and resemble the horns of a goat. These fruits are painful to step barefoot and can puncture bicycle tires or animal feet, paws, or hooves.

Goathead can grow up to 3 feet (90 cm) tall and prefers sandy and dry soils. It can tolerate drought, salinity, and low fertility. It spreads by seeds, which can remain viable in the soil for several years. Goathead can produce from 200 to 5,000 seeds per plant, which can be easily dispersed by wind, animals, or human activities. [13]

Barberry

Barberry is a common name for several species of shrubs or trees in the Berberidaceae family with spiny branches and leaves. They have yellow flowers in clusters and red or blue berries that are edible but sour.

Barberry is native to various regions of the world. However, some of them became invasive in the areas where they were introduced as ornamental plants or for erosion control.

Barberry bushes have thorny branches and produce berries that can attract birds and other animals, which then disperse the seeds. It can also spread by root suckers and can crowd out other plants.

Nettle

Nettle is a common name for several species of plants with stinging hairs on their stems and leaves. These hairs can inject chemicals into the skin, causing irritation, itching, and swelling.

The most widespread species of nettle is the common nettle, a perennial weed that can grow up to 4 feet (1.2 meters) tall. It has serrated leaves and tiny, inconspicuous green or purple flowers. It produces seeds that are dispersed mainly by wind.

Nettle is an invasive plant in gardens and lawns, as it can rapidly spread if left unchecked. It can also cause discomfort for humans and pets who come in contact with it. However, nettle can also have many benefits for wildlife and as a compost additive.

Nettle can provide food and shelter for many insects, such as butterflies, moths, and ladybugs. Nettle can also be used to make a nutrient-rich compost tea that can boost the growth of other plants.

Pro Tip: Wear gloves when dealing with nettles to avoid getting stung, or use a garden tool, such as a hoe or a fork, to remove them.

How to Safely Handle Weeds With Thorns

Weeds with thorns can be a pain in more than one way. They can injure your skin, damage your clothing, and interfere with your gardening.

Knowing how to safely handle and prevent them from spreading is important. Here are some tips on how to deal with weeds with thorns:

1. Identify The Weed
2. Managing Seeds and Young Seedlings
3. Protect Your Hands With Gloves
4. Tackling Weeds In Their Youthful Stage
5. Take Action Using A Weeding Hoe
6. Cover The Soil With Mulch
7. Use Natural Weed Control
8. Bring In Flowers To Replace Weeds
9. Apply Herbicides For Weed Control

1. Identify The Weed

The first step is to identify the weed that you are dealing with. Different weeds may have different characteristics, growth habits, and control methods.

Correctly identifying the weed is crucial as it will help you choose the best way to handle it safely and effectively. Some weeds may have specific names, such as spiny cocklebur, prickly lettuce, or jimsonweed, while others may have more general names, such as thistles or nettles.

Some weeds may be native or invasive, annual or perennial, herbaceous or woody. Some weeds may have medicinal or edible uses, while others may be toxic or allergenic. Knowing these details will help you decide how to deal with the weed.

2. Managing Seeds and Young Seedlings

Many weeds with thorns produce seeds that can spread by wind, water, animals, or human activities. These seeds can remain viable in the soil for years and germinate when the conditions are favorable. Therefore, preventing the weeds from producing and dispersing seeds is essential. You can do this by:

• Removing the flowers or seed heads before they mature and release seeds.
• Collecting and disposing of the seeds or burs that have fallen on the ground or attached to your clothing or tools.
• Using a pre-emergent herbicide that prevents the seeds from germinating.

You should also control the seedlings that emerge from the soil before they grow into mature plants. You can do this by:

• Pulling them out by hand when the soil is moist.
• Hoeing them out with a sharp tool that cuts them below the soil surface.
• Applying a post-emergent herbicide that kills them after they sprout.

3. Protect Your Hands With Gloves

When manually removing weeds with thorns, you should always wear gloves to protect your hands from bruises and irritation. You should also wear long sleeves, pants, and shoes to cover your skin and prevent contact with thorns.

Avoid touching your face or eyes with your gloves, as they may have traces of sap that can cause irritation or spines that can cause cuts and splinters.

4. Tackling Weeds In Their Youthful Stage

When weeds have thorns, it is better and safer to remove them when they are young and small. That way, they have fewer thorns that are much softer and are less likely to hurt your hands or cause splinters.

You should regularly inspect your garden or lawn for any signs of weed growth and act quickly before they become established and spread.

Pro Tip: When you are working with the soil in your garden, you may accidentally bring up some weed seeds that were buried deep and dormant. This can make them germinate and grow into new weeds.

5. Take Action Using A Weeding Hoe

A weeding hoe is a tool that has a sharp blade at the end of a long handle. It is used to cut off weeds at the soil level without having to bend down or touch them.

It is especially useful for removing weeds with thorns that have shallow roots, such as thistles or nettles. You should use a weeding hoe when the soil is dry and firm.

Pro Tip: Sharpen the weeding hoe blade regularly for better performance.

6. Cover The Soil With Mulch

Mulching is the practice of covering the soil with organic materials, such as straw or wood chips. Mulching can help suppress weed growth by blocking sunlight, reducing moisture evaporation, and adding nutrients to the soil.

It can also create a physical barrier that prevents weed seeds from reaching the soil surface, getting sunlight, and germinating. You should apply a thick layer of mulch around your desired plants, leaving some space for air circulation and water drainage.

Pro Tip: Avoid using inorganic materials such as plastic or rubber for mulching. These materials not only fail to enrich the soil with nutrients but can also get mixed into the soil and contaminate it.

7. Use Natural Weed Control

If you want to avoid using chemicals or herbicides to eliminate weeds with thorns, you can try some natural alternatives that are safer for you and the environment. Some of these alternatives are:

• Boiling water: You can pour boiling water over the weeds to scald and kill them instantly. This method is effective for small areas or spot treatments.
• Vinegar: You can spray vinegar on the weeds to lower their pH level and cause them to wilt and die. This method works best on young weeds or annuals.
• Salt: You can sprinkle salt on weeds to dehydrate and prevent them from absorbing water and nutrients. This method is suitable for areas where you do not want any growth, such as driveways or sidewalks.
• Corn gluten meal: You can spread corn gluten meal on the soil to inhibit weed seed germination and growth. This method is a pre-emergent treatment that should be applied before the weeds sprout, as it will not eliminate established weeds.

Pro Tip: Keep in mind that these natural alternatives can also damage the plants you want to keep. Therefore, apply them selectively and precisely.

8. Bring In Flowers To Replace Weeds

Another way to control weeds with thorns is to plant flowers that can compete with them and replace them. You should choose flowers native to your region, adapted to your soil and climate, and resistant to pests and diseases.

You should also choose flowers that have similar or higher growth rates, heights, and densities than the weeds you are trying to eliminate so that they can outgrow and outcompete them. Some examples of flowers that can replace weeds with thorns are:

• Sunflower is an annual flower that grows from 3 to 10 feet (0.9 to 3 meters) tall, depending on the variety. It has large and yellow flowers that attract pollinators during the flowering stage and birds when the seeds are formed. It can grow in various soils and conditions and produce edible seeds.
• Zinnia is an annual flower that grows from 6 inches to 4 feet (0.2 to 1.2 meters) tall, depending on the variety. It has colorful and showy flowers that attract butterflies and hummingbirds. It can grow in sunny and well-drained soils and tolerate heat and drought.
• Marigold is an annual or perennial flower that grows from 6 inches to 3 feet (0.2 to 0.9 meters) tall, depending on the variety. It has yellow, orange, or red flowers that have a strong scent. It can grow in poor and dry soils and repel garden nematodes and pests.

9. Apply Herbicides For Weed Control

If none of the above methods work for you, or if you have a large infestation of weeds with thorns, as a last resort, you can use herbicides to eliminate them. Choose a product labeled for the type of weed you are targeting, and follow the instructions carefully.

Also, wear protective gear, such as gloves, goggles, and a mask when applying the chemicals. You should avoid spraying the product on windy or rainy days, near water sources, or desirable plants.

Final Thoughts

Weeds with thorns are not only unsightly but also harmful to humans, animals, and other plants. They can cause injuries, infections, and allergies to people and pets. They can also damage your crops and gardens. Therefore, identify and eliminate them as soon as possible.

There are various methods to control and prevent these weeds, such as manual removal, mowing, mulching, and using natural or chemical products. You should always be careful when handling these weeds and wear protective gloves and clothing. By following these tips, you can enjoy a weed-free and thorn-free environment.

I hope you found this “Most Common Weeds With Thorns” article useful! If you like reading this, check out similar articles in our Garden Weeds section.

Want to share your thoughts, or have you read something you disagree with? Please send us an email! We would love to discuss it 🙂