In this article we’re going to talk about the top 11 most invasive garden plants, shrubs, and trees. Now, when we say invasive, we don’t mean like that annoying neighbor who always shows up unannounced. No, I’m talking about plants that are like that one friend who comes over and just never leaves. This list also contains those plants that you may not have heard of to be invasive. So, let’s get into it, starting with the most invasive of them all.
Japanese knotweed
![](https://upload.wikimedia.org/wikipedia/commons/1/19/Knotweed_1r.jpg)
Now, this plant is no joke. It’s like the Terminator of the plant world. Once it’s established, it’s almost impossible to get rid of. Japanese knotweed can grow up to 10cm a day, and it’ll push its way through anything in its path, including concrete. It’s been known to damage buildings, roads, and even flood defenses. If you see this bad boy in your garden, it’s time to call in the professionals.
Giant hogweed
This plant is like something out of a horror movie. It can grow up to 5 meters tall and has sap that can cause severe burns and even blindness. In fact, the UK government has listed giant hogweed as a Schedule 9 plant under the Wildlife and Countryside Act, which means it’s illegal to plant or cause this plant to grow in the wild. Stay away from this one, folks.
Tree of heaven
This tree may sound like something out of a fantasy novel, but it’s anything but magical. In fact, it’s more like a nightmare. It’s fast-growing, can grow up to 25 meters tall, and its roots can spread over 30 meters. Not only that, but it’s also incredibly tough to get rid of. It’ll keep coming back, even if you cut it down to the ground. Avoid this one like the plague.
Himalayan balsam
![](https://upload.wikimedia.org/wikipedia/commons/d/d8/20170806350DR_Neuhilbersdorf_%28Freiberg%29_Baumstubben.jpg)
This plant may look pretty, but it’s a real pain in the you-know-what. It can grow up to 2 meters tall, and its seeds can spread up to 7 meters away. Once it’s established, it can outcompete native plants and cause soil erosion. It’s so invasive that it’s actually illegal to plant or cause it to grow in the wild in the UK.
Skunk cabbage
This plant may not be as well-known as some of the others on this list, but it’s just as invasive. It can grow in wetlands and can quickly outcompete native species. Not only that, but it also emits a foul odor that smells like, well, skunk. So if you want to keep your garden smelling fresh, stay away from this one.
Russian olive
![](https://upload.wikimedia.org/wikipedia/commons/2/29/Russian_Olive.jpg)
This shrub may look pretty with its silvery leaves and yellow flowers, but it’s anything but harmless. It can grow up to 10 meters tall and can outcompete native plants. Not only that, but it’s also tough to get rid of, as it can sprout new growth from its roots. It’s so invasive that it’s been declared a noxious weed in some parts of the world.
Japanese barberry
This shrub may look innocent, but it’s a real troublemaker. It can grow up to 2 meters tall and has thorns that can be over 1cm long. Not only that, but it’s also a favorite spot for ticks, which can spread Lyme disease. So, if you want to keep your garden tick-free, steer clear of Japanese barberry.
![](https://upload.wikimedia.org/wikipedia/commons/7/74/%28ms%29_Berberis_thunbergii_12.jpg)
Tree privet
![](https://upload.wikimedia.org/wikipedia/commons/a/a8/LigustrumLucidumFlowers.jpg)
This tree may look nice in the garden, but it’s a real headache. It can grow up to 12 meters tall and can outcompete native plants. Not only that, but
it can also cause damage to buildings and walls as its roots can penetrate and weaken structures. Plus, it produces large amounts of berries that are toxic to birds and other wildlife. So, if you want to keep your garden safe and wildlife-friendly, skip the tree privet.
Russian vine
![](https://upload.wikimedia.org/wikipedia/commons/5/5f/Schlingkn%C3%B6terich_%28Fallopia_baldschuanica%29.jpg)
This fast-growing vine may seem like a great way to cover up an unsightly wall or fence, but it’s actually a nightmare. It can grow up to 20 meters in a single season, and its weight can cause damage to buildings and other structures. Not only that, but it can also outcompete native plants and cause soil erosion. If you want to keep your garden under control, avoid the Russian vine.
Yellow archangel
![](https://upload.wikimedia.org/wikipedia/commons/b/b3/Yellow_Archangel_%28Lamiastrum_galeobdolon%29_%285683632438%29.jpg)
This ground-covering plant may seem like a great way to add some color to your garden, but it’s a real troublemaker. It can quickly spread and outcompete native plants, and it can even become toxic to some wildlife. Plus, it can be tough to get rid of once it’s established. So, if you want to keep your garden healthy and wildlife-friendly, skip the yellow archangel.
Privet
![](https://upload.wikimedia.org/wikipedia/commons/c/ce/Leaves-4134.jpg)
Last but not least, we have the common privet. This shrub may be a common sight in many gardens, but it’s also invasive. It can grow up to 6 meters tall and can outcompete native plants. Plus, it produces large amounts of berries that are toxic to wildlife. If you want to keep your garden safe and healthy, avoid the privet.
So there you have it, folks, the top 11 most invasive garden plants, shrubs, and trees. Remember, just because a plant looks nice, doesn’t mean it’s good for your garden or the environment.
When in doubt, do your research and stick to native plants. Your garden, and the environment, will thank you for it.