Weeds with thorns are definitely the worst to find growing in your yard. Not only are they often invasive and difficult to eradicate, but they also hurt when you come in contact with them! That’s obviously not just a problem for you, but if you have children or pets who might get into them, they may end up with a painful rash after contact.
You may not even have a weed, it’s possible its a tree with thorns, but good thing we have a guide for those too. Below you will find 19 types of weeds with thorns that may be attacking your garden. If you can’t find it then you should leave a comment in the section below and we can help each other find out exactly what it is.
1. Spiny Sowthistle
Spiny sowthistle (Sonchus asper) is an annual plant native to Europe, Asia, and North Africa, but it is now found across North America, as far north as Alaska. It has yellow flowers similar to dandelions and grows in open ground. Try digging plants up, or cutting them off at the crown with a sharp hoe.
Cocklebur (Xanthium strumarium) is an annual weed found in most of the lower 48 states, southern Canada, and parts of Mexico. Its seedpods are covered with tiny hooks, and cling so well that they inspired the inventor of Velcro. Seedlings emerge in late spring and flower in August. Hoeing young plants before they set seed is the best method of control.
3. Burweed / Stickers
Burweed (Soliva sessilis) is native to South America and now grows widely along both coasts of North America. Seeds germinate in the fall and grow into mature plants the following spring, producing painful burs, making walking barefoot on your lawn an unpleasant experience. You’re unlikely to see them in a healthy lawn, but if they do appear, dig them out as soon as possible.
4. Prickly Lettuce
Prickly lettuce (Lactuca serriola) is native to Eurasia, but has become a widespread weed in North America. It’s the ancestor of cultivated lettuce, but instead of large, luscious leaves it has narrow, serrated leaves sprouting from a central stem, and produces yellow blooms similar to dandelions. The best way to deal with them is by pulling the young plants out, getting as much of the taproot as possible.
Beggarticks (Bidens bipinnata) is an annual plant native to the eastern United States and Ontario. Its white and yellow flowers set long, narrow seeds with spiked barbs on the end that cling to animal fur or clothing. Pull or dig out the young plants before they have a chance to set seed. Larger patches can be killed by repeated mowings before they flower.
6. Catchweed Bedstraw
Native to much of Europe and Asia, catchweed bedstraw (Galium aparine) has now become a weed all across North America. While the leaves are rough rather than thorny, they can irritate people with sensitive skin, and their small burs hook onto animal fur or clothing to spread their seeds. Hoe or pull the plants when young, and be prepared to come back later and repeat the process if they regrow from the root.
Horsenettle (Solanum carolinense) is a perennial weed that is native to a wide swath of North America. The fruits resemble tomatoes, but all parts of the plant are highly poisonous. Always wear gloves when handling this plant. The best way to get rid of it is by mowing or hoeing as soon as it blooms, and then once a month to prevent further growth.
8. Bull Thistle
The bull thistle (Cirsium vulgare) is also known as the common thistle. It’s native to Eurasia but is now a ubiquitous weed in North America. The best way to get rid of bull thistle in your lawn is by cutting off the stem an inch or 2 below the surface, preferably after buds have formed but before it sets seed.
Jimsonweed (Datura stramonium) is native to Texas, Mexico, Central America, and the Caribbean, but is also found now in other regions of the United States. It’s an annual plant that produces spiky burs. It’s toxic when consumed in large quantities. It can be controlled by regular mowing, which will prevent it from flowering and setting seed.
10. Spiny Pigweed
Spiny pigweed (Amaranthus spinosus) is native to South America but is now a common weed in eastern North America and California. It’s an annual that produces ½ inch spikes at every leaf node. It’s best to pull plants when young, or mow repeatedly if you have a large patch to deal with.
Burdock (Arctium) is originally from Europe and Asia, but has become naturalized in most of North America. The bristly burs contain thousands of seeds that spread easily, so if you have a problem with burdock, it’s imperative to deal with the plants before they flower and set seed. Dig out small plants, getting as much of the taproot as possible, and mow down larger specimens before they flower and set seed.
12. Blackberry Plants
It might sound delightful to have blackberry plants (Rubus allegheniensis) in your yard, but left to their own devices they can quickly take over. And if you’ve ever found yourself in a thicket of blackberries, you know how much their many thorns can scratch and hurt! If the shrubs are growing along the edge of your property, regular mowing will keep them from spreading into your lawn, while they can still form a useful barrier for wildlife such as deer.
13. Common Teasel
The common teasel (Dipsacus fullonum) is native to Europe and North Africa, but is now a common weed in most provinces and states in North America. These plants can grow as tall as 6 feet and live for multiple seasons, so early eradication is key. Dig or hand pull the plants when young, getting as much of the root as possible. Mowing is not recommended as the plants will regrow vigorously from the roots. 2-4-D works best on young plants.
14. Multiflora Rose
The multiflora rose (Rosa multiflora) originated in East Asia, but has become an invasive species in many parts of North America. It spreads so well that for a long time it was sold for erosion control, but now it’s become quite a problem, especially since it can reproduce by distributing seed, through its root system, or by canes rooting themselves and forming new plants. Early in the growing season, pull or cut plants, while herbicides are most effective from July to September.
Native to North America, Sandbur (Cenchrus longispinus) is an annual weed that usually stays close to the ground, producing spiky burs in late summer. Luckily, if your lawn is thick and healthy you’re unlikely to have a problem with this thorny weed. Fall fertilization will encourage the growth of grass to keep sandbur seedlings from gaining a foothold the following spring. Otherwise, your best bet is a pre-emergent herbicide.
16. Wild Rose
The wild rose (Rosa acicularis) is native to Asia and North America, and is often grown in wildflower gardens. However, it can get out of hand and start to move into more cultivated areas. If you want to get rid of a patch of wild roses, start by cutting the thorny stems down to within a few inches of the ground. That will make it easier to dig them out by the roots. Get as much as you can of the root system, as they can resprout from any fragments left behind.
Native to Asia, Africa, and Europe, goathead (Tribulus terrestris) is now an invasive weed in most of the United States, as well as British Columbia and Ontario. It’s an annual with yellow flowers that produces spiny seed pods that can cause injury when stepped on. The best way to eliminate this thorny weed from your property is by hoeing or hand pulling plants before they set seed.
18. Canada Thistle
Oddly enough, Canada thistle (Cirsium arvense) is not native to Canada, or even the Western Hemisphere. Instead, it originated in Europe and Asia, but now is found all across North America. It’s a perennial weed that has prickly leaves, and produces purple flowers that set thousands of seeds that spread on the wind. It also spreads by its roots, making it hard to eradicate. Hand pull or dig out the plants, removing as much of the roots as possible. You can also mow the plants repeatedly before they flower to weaken their systems and eventually kill them. Herbicides are most effective when applied in spring or fall.
Barberry (Berberis thunbergii) is native to Japan but now grows wild in Eastern North America as far as Iowa. It has long, sharp spines on its stems, which made it a popular choice for a natural barrier, but it spreads rapidly under ideal conditions. It’s been found to harbour ticks that carry Lyme disease, so you really don’t want it encroaching on your property. Whole plants can be pulled out in early spring, but be very careful of its sharp thorns. Make sure you get the entire root system. Flame weeding has also been found to be effective, and glyphosate and triclopyr herbicides are the safest herbicides to use.
How To Get Rid of Weeds with Thorns in Your Lawn?
There are different methods of eradicating weeds in your lawn.
If you have thick, lush grass with no bare spots, weeds are going to have a hard time taking root, so your first and best line of defense is keeping your lawn healthy.
When you do see weeds always start with organic methods. Only use herbicides when nothing else has worked. Chemical herbicides can damage plants you want to keep, and present a danger to children and pets.
If you remove weeds before they set seed, you’ve stopped them from reproducing, which is the most important thing. Once a weed has bloomed, you don’t have much time to eliminate them.
Try pulling weeds out by hand. However, because weeds with thorns will cause pain or a rash, always wear tough garden gloves, such as leather, that the thorns won’t be able to pierce. Try to get the whole root along with the top growth. If you leave behind even a small piece of the root, many weeds can resprout.
If your soil is too hard or the weed is deeply rooted, use a trowel or spade to get out as much as possible.
You can take out a large patch of weeds by mowing them repeatedly as close to the soil surface as possible. It may take a month or more, but if the roots don’t get any nourishment, the plants will die.
A great way to kill weeds with thorns is with a flame weeder. This has a propane cylinder that fuels a flame on a wand. Zap your weeds and watch them shrivel and die!
You may have success spraying weeds with horticultural vinegar, which starts at concentrations of 20% acetic acid up to 45%. Normal household vinegar won’t do much, and with the strong stuff you do have to be careful not to get it on plants you don’t want to kill.
If nothing else works, you can use herbicides such as 2-4-D. However, you must be very careful when applying these chemicals to your lawn. Always wear protective gear and keep children and pets away for a few days after applying it.
When you are trying to maintain a beautiful landscape, thorny weeds like these not only detract from your efforts but also can inflict injury on anyone unfortunate enough to come in contact with them. Early identification and eradication, as well as encouraging thick, healthy grass, will help you keep your yard looking its best!
Janice is a retired High School teacher who is spending her leisure years keeping busy with all sorts of projects. Aside from freelance writing, she’s an enthusiastic amateur chef, home wine maker, and tends a large raised-bed vegetable garden, while at the same time running a Bed & Breakfast.