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Invasive garden plants


12 Common Invasive Plants You Should Never Grow In Your Garden

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Broadly defined, invasive plants are non-native species introduced to a particular region where they are able to spread far and wide.

Exotic plants from faraway lands may be beautiful but there is no way to stop them from escaping the confines of your garden through the dispersion of seeds or by creeping underground rhizomes.

The addition of foreign cultivars to the natural landscape has had a real and lasting impact on the flora and fauna that rely on native species to survive.

How Invasive Plants Threaten Native Ecosystems

Many of the invasive transplants found in the wilderness of North America originally hailed from Europe and Asia, brought over by settlers who desired some familiar ornamentals in their new home.

Once established in a new location, invasive species cause harm to the environment and local ecosystems by outcompeting native plants and decreasing overall biodiversity.

Invasive plants are able to spread so successfully through a number of traits: they grow fast, reproduce quickly, adapt to a wide range of environmental conditions, and can even alter their growth habits to better suit the new location.

Additionally, invasives may thrive in their new home due to an absence of insects or diseases that would normally keep their numbers in check in their natural habitat.

Invasive species are among the main drivers of the loss of biodiversity globally, creating monocultures that cause native plants to go extinct, or to become hybridized through cross pollination between related native plants.

Some invasive plants are classified as noxious weeds that are “injurious” to humans and wildlife. These produce allergens, or are toxic by contact or ingestion.

Not all plants that come from a different continent are invasive, and even some plants that are native to North America can be classed as noxious or aggressive when they land in a state they are not indigenous to. This is why it is so important to research the plants you wish to grow to make sure they are a part of your local biome.

Sadly, plenty of plant nurseries and online shops will eagerly sell you the seeds and starts of invasive plants regardless of their ecological impact.

These cultivars are still widely sold throughout the United States today.

Choose to grow native plants instead – not only are they beautiful and low maintenance, they help support the food web while preserving plant diversity.

1.

Butterfly Bush (Buddleja davidii)

Butterfly bush was introduced to North America around 1900, originally hailing from Japan and China.

It has since escaped cultivation through copious self-seeding dispersed by wind, spreading aggressively in eastern and western states. It is classified as a noxious weed in Oregon and Washington.

Butterfly bush produces fragrant and showy arching panicles with densely clustered tiny flowers. And while it’s true that this shrub provides a source of nectar for pollinators, it is actually detrimental to butterflies.

Although adult butterflies will feed on its nectar, butterfly larvae (caterpillars) cannot use the leaves of the butterfly bush as a food source. Because butterfly bush doesn’t support the entire lifecycle of butterflies, it is quite harmful when it displaces native plants in forests and meadows that caterpillars need to survive.

 
Grow this instead:Butterfly weed is a great alternative to the invasive butterfly bush.

2.

Chinese Wisteria (Wisteria sinensis)

Wisteria is a gorgeous woody vine that blooms with drooping clusters of bluish purple flowers in spring.

While it looks absolutely stunning growing up walls and other structures, its vines will eventually become heavy and quite massive. The vines can make their way into cracks and crevices, damaging the façades of homes, garages, and sheds.

While gardeners should be prepared for plenty of pruning and maintenance with wisteria, the Chinese variety is especially problematic.

First introduced to the United States in the early 1800s, Chinese wisteria is a very aggressive grower that has invaded the wilderness of the eastern and southern states. Because it grows so fast and becomes so massive, it kills trees and shrubs by girdling them and blocks out sunlight from reaching the forest understory.

If you love the look of wisteria, grow varieties that are indigenous to the region. And when planting, do so away from your home. Train wisteria to grow on freestanding structures like heavy duty pergolas or arbors.

Grow this instead:

3.

Burning Bush (Euonymus alatus)

Also known as winged spindle tree and winged euonymus, burning bush is a spreading deciduous shrub with leaves that turn a vibrant scarlet hue in autumn.

A native of northeastern Asia, burning bush was first brought over in the 1860s. Since then it has spread to at least 21 states, establishing itself in forests, fields, and roadsides in dense thickets where it crowds out native plants.

Burning bush is able to spread far and wide because birds and other wildlife disperse seeds from eating the berries it produces.

Grow this instead:

4.

English Ivy (Hedera helix)

Grown as a climbing vine and ground cover, English ivy is a lovely façade green with its lobed deep green foliage. Since it is drought tolerant and adaptable to heavy shade, it is a popular vine that is still widely sold in the US.

English ivy is much better when kept indoors as a houseplant. When planted outdoors, it escapes cultivation with the help of birds that disperse its seeds.

In the wilderness, it grows quickly and aggressively along the ground, choking out native vegetation. Trees in its path become infested, blocking out sunlight from the tree’s foliage, which will slowly kill the tree.

Worse still, English ivy is a carrier of bacterial leaf scorch (Xylella fastidosa), a plant pathogen that can have a devastating impact of many types of trees.

Grow this instead:

5.

Japanese Barberry (Berberis thunbergii)

Japanese barberry is a small, thorny, deciduous shrub with paddle shaped leaves, often used as a hedge in landscaping. It is available in numerous cultivars with red, orange, purple, yellow, and variegated hues.

Introduced to the US in the 1860s, it has colonized large swaths of the Great Lakes region by adapting to a wide range of habitats including wetlands, woodlands, and open fields.

While Japanese barberry displaces native species, it also changes the chemistry of the soil it grows in by making soils more alkaline and altering soil biota.

Its dense habit creates high humidity within its foliage, providing a safe harbor for ticks.  In fact, it has been theorized that the increase in Lyme disease is directly related to the spread of Japanese barberry.

Grow this instead:

6.

Norway Maple (Acer platanoides)

An European transplant introduced to North America in the 1750s, Norway maple has since come to dominate forests in the northern parts of the US and Canada.

Although it was initially prized for its easygoing nature, being tolerant of drought, heat, air pollution, and a wide range of soils, Norway maple has had a dramatic effect on the character and structure of our woodland areas.

Norway maple is a fast grower that freely reseeds itself. Its shallow root system and large canopy means very little can grow beneath it. Blocking sunlight and starving plants for moisture, it overwhelms the habitat and creates forest monocultures.

Especially troubling is it directly threatens the survival of native maple trees, since deer and other critters will avoid eating the leaves of the Norway maple and will consume native species instead.

Grow this instead:

7.

Japanese Honeysuckle (Lonicera japonica)

Japanese honeysuckle is a fragrant twining vine bearing white to yellow tubular flowers from June to October.

Although lovely, Japanese honeysuckle is an extremely aggressive spreader, creeping in dense mats along the ground and suffocating any trees and shrubs it climbs on. It shades out everything that happens to grow below it.

Initially planted in New York in 1806, Japanese honeysuckle now occupies vast tracts of the Eastern Seaboard.

Plant this instead:

8.

Winter Creeper (Euonymus fortunei)

A dense, woody, broadleaf evergreen, winter creeper is a versatile plant with many habits: mounding shrub, hedge, climbing vine, or creeping ground cover.

Winter creeper readily self-seeds and can be found growing in the wilds in the eastern half of the US. It invades forest areas that have been opened up due to fires, insects, or wind.

Because it vigorously spreads across the ground, it chokes out low growing plants and seedlings. Clinging to the bark of trees, the higher it grows, the farther its seeds can be carried by the wind.

Grow this instead:

9.

Autumn Olive (Elaeagnus umbellata)

Autumn olive, or autumnberry, is an attractive sprawling shrub with thorny stems and silvery green elliptical leaves. Indigenous to Eastern Asia, it was first brought to the US in the 1830s to rewild and restore old mining sites.

At one time, it was advised to grow this shrub for its many positive attributes, including erosion control, as a windbreak, and for its edible fruit. Autumn olive is also a nitrogen fixer that thrives in barren landscapes.

Despite its good qualities, autumn olive has since invaded many areas of the eastern and central US, forming dense, impenetrable thickets that displaces native plants.

It has been able to spread so successfully because it grows quickly and reproduces via root suckers and self-seeding. A single autumn olive plant can produce 80 pounds of fruit (that contain roughly 200,000 seeds) each season.

Grow this instead:

10.

Border Privet (Ligustrum obtusifolium)

Commonly cultivated in the northern parts of the US as a hedge and privacy screen, border privet is a fast growing, deciduous shrub that hails from Asia.

Border privet generously self-seeds each season and is tolerant of wide range of soils and drought. It has escaped from home gardens in the Midwest to form dense thickets that crowd out native species.

Grow this instead:

11.

Maiden Silvergrass (Miscanthus sinensis)

Maiden silvergrass, also known as Chinese or Japanese silvergrass, is a clump forming plant that provides color and texture in every season.

Freely self-seeding, it has spread to more than 25 states through Central and Eastern US, and can be found as far west as California.

It is also highly flammable, and increases the fire risk of any area it invades.

Grow this instead:

12.

Golden Bamboo (Phyllostachys aurea)

Golden bamboo is a vigorous, fast growing evergreen that turns yellow as its tall poles mature. It is frequently used as a hedge or privacy screen in home gardens.

A “running” type of bamboo, it reproduces through underground rhizomes that can emerge from the soil quite a distance from the parent plant.

Once golden bamboo is planted at a site, it is very difficult to remove. It can take years of repeatedly digging up the root system to fully eradicate it.

Brought to the US from China in the 1880s as an ornamental, golden bamboo has since invaded several southern states by forming dense monocultures that displace native plants.

Grow this instead:

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Invasive plants: 12 plants to avoid growing in your yard

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(Image credit: Premium Stock Photography GmbH/Alamy Stock Photo)

Invasive plants are those that have been introduced by humans and which then go on to damage natural habitats. They grow and spread rapidly, smother native plants and flowers, often overwhelm native animal and insect life and may transform a landscape dramatically.

Invasives can be trees, shrubs, vines, perennials, annuals or aquatics and are often first planted because they are useful or attractive plants for our yards. Some native plants can also spread rapidly, but these are not usually classified as invasive.

Many invasive plants were deliberately introduced to natural habitats, for various reasons, then spread unexpectedly. Some escaped from gardens and yards, some were accidentally introduced.

It is important to remember that many plants are invasive in some parts of the country, but perfectly well-behaved in others. So each state has its own list of invasive species, your local Cooperative Extension Service or local nurseries can provide detailed information.

Controlling invasive plants is often difficult. As with how to get rid of weeds, hand pulling or digging is a widespread approach, and in some areas insects or fungi that feed on a particular invasive have been introduced. Weed killers are also sometimes used but come with their own risks. Deer can make the problem worse by eating native plants but not invasives.

For most of us the crucial thing is to make sure invasive plants aren't included in our yards and, if we see any invasives arrive, to pull them out straight away. 

12 invasive plants to be aware of

Our list of 12 of the most common invasive plants for you to avoid will help to prevent these invasive species from becoming even more problematic in your area. 

1. Japanese barberry (Berberis thunbergii)

(Image credit: Lena Maximova/Alamy Stock Photo)

This thorny shade-tolerant deciduous shrub, with small rounded leaves, clusters of small yellow spring flowers and red berries, colonizes the floor of deciduous forest in the north and east. At first, it often spreads from our backyards, as ornamental varieties with purple or variegated leaves are planted in gardens. Many also feature attractive fall color.

Once plants have established themselves their spread is encouraged by the fact that they are not eaten by deer.

Varieties that do not produce seeds, and therefore spread less easily, are now being introduced but it is not yet clear if they are always 100% seed free.

2. Butterfly bush (Buddleja davidii)

(Image credit: Jani-Markus Häsä/Alamy Stock Photo)

A vigorous, sun-loving deciduous shrub that features pointed greyish leaves and long spikes crowded with tiny, sweetly fragrant, nectar-rich summer flowers. Garden varieties come in a wide range of rich and pastel colors, but as they establish themselves outside gardens they tend to revert to pale mauve.

Widely seen in the east and west of the US, plants are killed to ground – or killed completely - in zone 5 where they may not seed at all.

Often planted for its popularity with butterflies and hummingbirds, once escaped it smothers native vegetation in sunny, well-drained sites including fields, roadsides, abandoned railroads and mines, on dry slopes and often damages garden walls by rooting in the cracks.

3. Chinese wisteria (Wisteria sinensis)

(Image credit: Jackie Nix/Alamy Stock Photo)

An extremely vigorous, twining, deciduous vine found in the east and south of the US, rapidly climbing both deciduous and evergreen trees and reaching up to 60ft with large leaves split into pairs of opposite leaflets.  

Mauve pea-flowers are carried in flamboyant dangling strings up to 16in long in spring, before the leaves, and are followed by long, flat, hairy seed pods.

As well as smothering native vines, and the foliage of native trees, the mass of growth in the tops of mature trees makes them vulnerable to storm damage. Tight twining stems may also girdle the trees’ branches.

4. Cogon grass (Imperata cylindrica)

(Image credit: Danita Delimont/Alamy Stock Photo)

Established in the east and south from Virginia to Mississippi, and continuing to spread in the south, this aggressive creeping perennial grass is considered one of the worst invasive species in the world.

Reaching 1-6ft in height, the pale foliage becomes biscuit-colored as it ages and the plants produce silver feathery seed heads. Garden varieties are sometimes grown.

Cogon grass is found in dense colonies along highways, on sand dunes, in forests and open fields, and as an agricultural weed. The roots produce a chemical that stunts the growth of other plants allowing it to establish dense carpets that smother native plants.

5. English ivy (Hedera helix)

(Image credit: Studio75/Alamy Stock Photo)

English ivy is a ground covering plant and tree climbing evergreen vine with small glossy leaves with three to five lobes, then large leaves with creamy flowers and black winter berries as it matures. The stems that climb tree trunks produce very short roots fixing the shoots to the bark but they do not suck sap from the tree.

The ground covering growth smothers many native flowers. As it climbs into the crown of trees, the mass of evergreen growth can weigh down and break branches, especially in gales or when heavy with snow. Ivy is found in the east, south and west and is eaten by deer. 

6. Japanese honeysuckle (Lonicera japonica)

(Image credit: Sari O'Neal/Alamy Stock Photo)

Found in eastern states from Maine to Florida and across to Wisconsin and Texas, this rampant twining type of honeysuckle grows in sun or shade in prairies and flood plains, forest margins and clearings. It spreads across the ground, twines into shrubs and trees, collapses highway fences, and smothers everything in its path.

Evergreen in mild zones and deciduous in colder areas, fragrant white summer flowers turn creamy with age and are followed by red berries ripening to black. 

7. Eurasian Water Milfoil (Myriophyllum spicatum)

(Image credit: Emmanuel Lattes/Alamy Stock Photo)

This submerged, usually aquatic perennial plant features extended stems up to 8ft long carrying clusters of feathery foliage at intervals and 6in spikes of small red summer flowers held above the surface.

In still and slow moving water, Eurasian water Milfoil spreads into dense mats that not only crowd out native aquatic plants but also impede swimming and boating. The dense growth also blocks light from reaching deeper into the water and can also disrupt habitats for fish, and insects and other aquatic life.

Eurasian water milfoil was originally spread through the aquatics trade but, once established, fragments of stems are carried to new areas.

Looking for aquatic plants for your yard? There are plenty of suggestions in our guide to the best pond plants. 

8. Japanese knotweed (Reynoutria japonica)

(Image credit: blickwinkel / Alamy Stock Photo)

Originally introduced as an ornamental, and now sometimes grown as a medicinal herb, Japanese knotweed is a tall dominant perennial that smothers everything in its path. It develops large stands along rivers and other watercourses, roadsides, and waste ground – often associated with human activity such as road construction.

Roots penetrate cracks in foundations, shoots will force their way through asphalt and also penetrate and clog drains. The stems can grow 4in in a day and are topped in summer with attractive white plumes.

9. Kudzu vine (Pueraria montana)

(Image credit: Norman Barrett/Alamy Stock Photo)

Widely known as 'the vine that ate the South', kudzu is less of a threat than many invasive plants but can still be a menace in some areas, especially along highways.  

Kudzu is an exceptionally vigorous perennial vine whose alternating leaves are split into three large lobes. Once established it produces tight spikes of purple flowers.

Its rampant growth smothers native plants and its weight as it scrambles through the forest canopy can break branches.

The leaves, flowers and roots are all edible and are also popular with grazing cattle.

10. Multiflora rose (Rosa multiflora)

(Image credit: George Ostertag/Alamy Stock Photo)

If you're a fan of having roses in your yard, this is one to avoid. Formerly planted on highway medians to reduce headlight glare and produce impenetrable thickets as a crash barrier, it soon spread to roadsides, pastures and many other open sites.

This deciduous shrub with clusters of pretty white flowers followed by small red fruits was also once planted to encourage wildlife. However, its thorny tangled thickets smother native vegetation and a single plant can produce hundreds of thousands of seeds in a single season.

Find alternative types of roses in our dedicated guide. 

11. Common periwinkle (Vinca minor)

(Image credit: Bob Gibbons/Alamy Stock Photo)

This adaptable evergreen, low maintenance ground cover plant has escaped from gardens, especially abandoned homesteads, and spread into many damp and shaded habitats mainly across the east and south where it smothers the forest flowers.  

Its opposite pairs of dark green leaves create an overlapping smothering carpet of growth which may sprawl into the lower branches of native shrubs. In spring, the pretty five-petalled flowers open like blue or white propellers.

The similar but larger bigleaf periwinkle (Vinca major), is also a vigorous invasive but is restricted to warmer zones, 7-9.

The roots of periwinkles are relatively shallow so easier to remove than those of many invasive plants.

12. Purple loosestrife (Lythrum salicaria)

(Image credit: Don Johnston_PL/Alamy Stock Photo)

Introduced from Europe as a flower for garden borders, and on a larger scale for honey production, this hardy perennial can spread quickly into wet places, such as streams and lakesides, ditches and especially marshes.  

Its colorful stands of purplish pink flowers in vertical spikes can dominate large areas, although there is some evidence that its presence can improve insect populations. Named varieties with flowers in white, pale pink or red shades are sometimes still offered by nurseries but should be avoided.

Growing in wet habitats across almost the whole country, effective control can be difficult.

Can I use weed killers on invasive plants in my yard?

Always think carefully about using weed killers in your yard. Many will kill any plants they touch, so you may kill your flowers and bushes by mistake. Spray can drift on to your kitchen garden or into your neighbor’s yard and some weed killers can severely damage aquatic habitats such as backyard ponds.

Some gardeners will decide not to use any weed killers but, for some invasives, weed killers can be the only option.

You can often increase the effectiveness of weed killers, and reduce the danger of killing your garden plants, by cutting back your invasives to the ground and spraying weed killer on the vigorous new growth that develops.

This method can also be effective if you want to know how to kill bindweed and how to get rid of poison ivy. 

(Image credit: Enis72/Alamy Stock Photo)

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Different lists of invasive plants seem to include different varieties.

Who can I trust?

Different invasive plants thrive and cause trouble in different parts of the country. So kudzu vine is a big problem from Virginia and the Carolinas, through Florida, Alabama, and Louisiana but rarely seen at all from Montana and Idaho, across the Dakotas to Wisconsin and Michigan.

So it pays to look for local advice on what to avoid planting in your area and how to deal with invasive plant problems that you may face.

I’d like to plant a tree of Heaven in my yard, but my neighbor says it’s banned. Is that right?

Tree of Heaven is an attractive, fast growing, deciduous tree that smothers and crowds out native trees, shrubs and flowers. It is listed as a noxious weed in 46 states so it is simplest to say that it should not be planted anywhere. 

Its spread is helped by its tolerance of poor soils, its vigorous root system that can penetrate foundations and damage paving, plus the ability of the seeds to sprout and develop quickly in harsh urban environments as well as ditches, disturbed and abandoned industrial sites, and along highways.  

The winged seed is carried on the wind and seedlings have been found 300ft from the nearest seed-bearing tree.

Graham Rice is a garden writer who has won awards for his work online, and in books and magazines, on both sides of the Atlantic. He is a member of a number of Royal Horticultural Society committees and the recipient of the 2021 Garden Media Guild Lifetime Achievement Award. 

Dangerous invasive species - not only the terrible and familiar hogweed

Recall that invasive species are those species of living organisms (plants or animals) that have spread to originally unusual natural habitats due to human activities and now threaten local biological diversity.

No matter how funny the concept of plant-aggressor or plant-invader may sound for a person far from biology, the problem of invasions (intrusion into a foreign ecosystem) is one of the largest environmental problems of our time. Invasion of alien species poses a significant threat not only to biological diversity (when plants and animals common to the area are simply replaced by aggressive aliens), but also to the economy of agriculture and forestry, and even sometimes to human health.

And if modern summer residents are more or less aware of the dangers of some invasive plants (as, for example, happened with Sosnowsky's hogweed, a poisonous, very large and very rapidly spreading weed), then about the "occupational moods" of some others, sometimes very nice-looking cultures, still do not even guess - and very much in vain! In addition to harming nature and your own suburban area "in the future", planting some of these plants near the house or ignoring them (non-destruction) is already facing a considerable fine - and the list of such species is constantly updated.

Specialists of the Ministry of Ecology have prepared a list of the most dangerous invasive plant species that are prohibited from being used in improvement programs in the Moscow region, introduction and acclimatization. Let's get acquainted with the most common cultures from this list together.

We won’t mention the infamous cow parsnip, for which residents of the Moscow region have already paid a lot of fines, since 2018, we will focus on less obvious, at first glance, and sometimes very decorative invasive species that the Ministry of Ecology put on the “black list” and so far only strongly does not recommend planting near their homes, but is already considering other measures. Be vigilant, many of these crops are still freely sold in garden centers - they were originally actively used in landscaping precisely because of the speed of their growth, reproduction and the formation of a lush green mass!

Ash Maple (American, California)

This maple is originally from North America, but has long since formed its own vast range in Europe, actively crowding out native species and even becoming a threat to local ecosystems in some places. If its decorative garden forms delight the breeders of this culture of incredible beauty with colored foliage (pink, bronze, green with borders, reddish-brown, light yellow, etc.), then wild trees can become a real disaster for parks and forest plantations.

This maple is very winter-hardy and undemanding to soil conditions. It has a very fast growth rate and is resistant to air pollution. Having “emerged” from cultivated plantations and easily managed to take root in local vegetation, the American maple, due to its very high ecological plasticity, today poses a serious threat to biological diversity. The ability of this plant to form multi-tiered thickets much faster than other species with the help of numerous and very strong root and stump shoots, as well as to secrete inhibitory substances (inhibiting the growth of other plants) makes it difficult to renew native species and makes ash-leaved maple one of the most aggressive woody weeds in the forest zone Eurasia (weed-parasite). In addition, its pollen (and there is a lot of it, because the species is wind-pollinated) is a strong allergen for people. In everyday life, botanists even got accustomed to the unofficial nickname of this tree - the killer maple.

As for the fight against the malicious aggressor, in some areas the growth of its population is already being curbed and gradually replaced by native trees and shrubs.

But be careful - since the communities of the ash-leaved maple still belong to the third category of green spaces by law, cutting or damaging them without the appropriate permits entails administrative liability.

Goldenrod (golden rose)

This herbaceous perennial of the Asteraceae family is undeniably familiar to absolutely all summer residents. Tall plants with narrow leaves and caps of golden flowers were at one time actively promoted as an ideal ornamental crop for a summer cottage. Judge for yourself - goldenrod is very beautiful, blooms until the very cold, grows quickly, easily reproduces even on its own, unpretentious to soils, requires almost no care, tolerates strong shading, excellent honey plant, pollinated by a wide range of insects, exceptionally winter-hardy. In addition, it is quite a valuable medicinal plant. It would seem - what could go wrong?

In fact, due to its incredible unpretentiousness and active uncontrolled reproduction, goldenrod began to literally crowd out the local, not so adaptive flora. Goldenrod has a powerful, fast-growing horizontal rhizome and a huge number of small, light seeds that are easily dispersed by the wind. Forming dense high dense thickets, producing inhibitory substances that depress the root system of "neighbors", and actively spreading by self-sowing, this native of distant North America (goldenrod began to spread intensively in Europe only after the 1850s) very quickly becomes the dominant any territory, leaving no chance for not so large and aggressive native species and being a real mortal threat for them.

The list of especially dangerous in terms of invasion includes two species of goldenrod - Canadian and giant.

If this plant is present in your area, the only way to combat its uncontrolled spread is to cut off the flowers immediately after withering, preventing the formation of seeds. If it seems to you that one seeded plant in your flower bed will not do much harm, think about how many tenacious seeds the wind and insects will spread to neighboring areas and to the nearest undergrowth.

One effective way to completely get rid of goldenrod is to mow twice to four times a year (in May and August) for several years, followed by mulching or digging up the soil during the summer when the weather is dry. Young plants are also sensitive to herbicides.

Multi-leaved lupine

Yes, yes, you were not mistaken - a valuable green manure from the Legume family and just a very pretty perennial that blooms with huge white, pink or purple "candles" is also an invasive species that poses a danger to the native flora.

Lupine "came" to Eurasia, all from the same North America, and due to its beauty, unpretentiousness and resistance to the most unfavorable growing conditions, it quickly became at first a favorite of gardeners, and then a dangerous invader species, especially when it began to be sown by road organizations in entire "fields "for the good purposes of improving the quality of soils and fixing soils.

Why is lupine dangerous? Its influence on native species is most obvious in the case of the formation of extensive, rather dense thickets that suppress and displace natural vegetation - lupine is more likely to be a so-called "soft invasive species", in controlling the expansion of which they themselves can be of great benefit.

Lupine grows easily on any soil, quickly propagates by seeds or dividing the bush, grows a lot of green mass, enriches the soil with nitrogen, available phosphorus, organic matter, "raises" nutrients from the depths to the surface. In addition, bears and larvae of the cockchafer are afraid of lupine.

In the case of growing lupine as green manure in your garden or several bushes in a flower bed, you can get rid of it by the usual timely mowing of the crop before the formation of seeds. In the case of mass growth of lupine, measures to combat it should be either treatment with permitted herbicides, or (which is much more environmentally friendly and safe) regular mowing twice a year and grazing sheep herds.

Reinutria japonica (Highlander Sakhalin)

This perennial is a distant relative of buckwheat. But, unlike this valuable cereal crop, rheinutria, brought to us from the Far East, is the most dangerous invasive species.

In Russia, there is no control over the state of rheinutria populations yet, but the experience of European countries and the United States shows that uncontrolled growth of the species can lead to significant economic losses. This weed is truly indestructible - it has a creeping, highly branched rhizome and a strongly branched, fast-growing crown with large leaves. Not only that, having settled in your garden, rheinutria will instantly grow and begin to shade all plants nearby, literally "soul" them and take resources, its rhizomes are so strong that they can destroy asphalt, damage hydraulic structures, foundations and light buildings! Also, rheinutria thickets increase soil erosion during spring floods, because. local soddy species are forced out, and the soil is not protected from washout.

This weed is incredibly difficult to control, since the growth of the underground mass greatly exceeds the growth of the above-ground, which often misleads gardeners - mowing will not help here, herbicides (except for the most powerful and dangerous to the environment) practically do not work on it. Various chemicals are currently being tested, as well as biological control measures are being developed for the plant (such as the use of a rust fungus and special beetles).

Successful control of rheinutria requires painstaking work and a combination of different methods of control of this invasive species, which will help at least contain the spread of a dangerous weed.

Fieldfare

This frost-resistant, fast-growing shrub with numerous strong erect shoots, growing to a height of 2-3 m, got its name for the similarity of leaves with mountain ash, although it belongs to a completely different botanical genus.

This plant is native to Asia, after being introduced and cultivated in many countries of the world primarily as an ornamental (for its openwork crown that changes color during the season, and fragrant fluffy white inflorescences-panicles that adorn the bush for up to three months in a row) and melliferous, and also for fixing slopes, slopes and damp unsteady sandy soils. Fieldfare is undemanding to soils, wind-resistant and frost-resistant, resistant to shading and anthropogenic conditions.

Why is fieldfare dangerous for native species? In a single copy in your area - perhaps a few, it can rather be attributed to the very "soft invasive species". But in nature, rapidly growing and multiplying (by seeds, root offspring, root cuttings and lignified shoot cuttings), fieldfare is able to form continuous extensive thickets under the forest canopy and displace local plants, which negatively affects the composition and structure of forest communities.

If you have any of the above crops growing in your area, the first thing to consider is whether you are doing enough to prevent the uncontrolled spread of invasive species "over the fence". And if you are interested in a complete list of alien plant species in the ecosystems of the middle zone, you can find it in the so-called Black Book of Russian Flora, published with the assistance of specialists from the Russian Academy of Sciences.

19 most dangerous invasive plant species in Russia. Description and photo — Botanichka

Invasive, or invasive plant species are called alien species that have entered a new territory and began to actively multiply, displacing native species. Many of the invader plants harm human health, the environment and the species diversity of the plant world. Most of these plants came to us from America, some from other countries. Some, for example, Sosnovsky's hogweed, were induced on purpose, some "escaped" from botanical gardens or summer cottages. According to modern research, invasive plants in Russia are currently absent in the territory of Karelia, and their largest number (71 species) was found in the Kaluga region. In this article I will talk about the most dangerous and common invasive plant species in Russia.

19 most dangerous invasive plant species in Russia

A textbook example of an invasive plant is the growth of prickly pear cactus in Australia, imported from South America. "Alien" actively grew on pastures, mass death of livestock began to occur. The cactus moth butterfly helped to cope with the prickly pear; a monument was even erected to its caterpillars in 1938.

1. Ambrosia artemisiifolia

Ambrosia artemisia ( Ambrosia artemisiifolia ) came to Russia in 1918. Its pollen is a strong allergen that can cause anaphylactic shock or Quincke's edema. In the southern regions of Russia, during the flowering of ragweed, the number of people diagnosed with pollinosis, forced to take a sick leave, increases by 40%.

Ambrosia artemisiifolia. © Harry Rose

In addition, ragweed greatly dries out the soil, which greatly reduces the yield of cultivated plants. One ragweed mother plant can produce one hundred thousand seeds - several hectares can be sown with this amount. Ragweed spreads along highways and railroad tracks. It is on the list of quarantine plants.

It is known that, for example, it came to Ukraine with contaminated grain through Mariupol and spread widely throughout the country in just 60 years. But Belarus was able to cope with this dangerous invader by using herbicides.

Read more about this dangerous plant in the article Beware of Ambrosia! How to destroy a weed that is dangerous to health?

2. Ailanthus highest

Ailanthus highest ( Ailanthus altissima ) was used in the Crimea for landscaping. The plant is able to multiply very quickly by rhizomatous layering, forms thickets along ravines, along highways. It has no natural pests due to an unpleasant odor. Aggressively crowds out native plant species.

Ailanthus altissima. © julia_HalleFotoFan

3. White locust

White locust, or Robinia pseudoacacia ( Robinia pseudoacacia ) actively grows in clearings, propagating by root shoots, and quickly crowds out local species. Homeland - North America. Dangerous insect pests can nest on Robinia plants.

White locust, or Robinia pseudoacacia (Robinia pseudoacacia). © lh3treeid

4. Hogweed

Heracleum sosnowskyi ( Heracleum sosnowskyi ) was introduced from the Caucasus as a plant suitable for fermentation as silage for cattle feed. Its use continued until the early 1980s. It was recognized as a dangerous weed only in 2015.

Sosnovsky's hogweed (Heracleum sosnowskyi)

Most common in the central regions of Russia and in the North-West, but has already reached the Arctic. In sunny weather, the juice of the plant, in contact with the skin, causes severe chemical burns (photodermatitis), which do not heal for several months. In addition, vomiting and dizziness may occur for several days.

If hogweed juice gets on unprotected skin, doctors recommend removing the juice immediately with a tissue, washing it off with a solution of baking soda and covering it from sunlight. If blisters appear, consult a doctor, in no case do not open it yourself. Only in the Moscow region, more than 30 thousand hectares of area are infected with this plant.

Another species Mantegazzi hogweed ( Heracleum mantegazzianum ) is even more poisonous. Every year the area of ​​its distribution increases by more than 10%. The plant surrounds rural settlements, penetrates into city parks and even enters reserves and reserves. It is very important to fight the invader on the ground with your own forces.

Mantegazzi hogweed (Heracleum mantegazzianum). © naturgucker.de

Interestingly, in Kamchatka, brown bears eat hogweed.
In some regions of Russia, including the Moscow region, individuals and legal entities, on whose plots hogweed is found, are required not only to destroy the plants, but also to pay a fine.

It is recommended to cut it before flowering and again after 30-40 days. The tops must be destroyed. On household plots, single plants can be cut with a sharpened shovel on an elongated handle. It is necessary to work in cloudy weather and remember to protect the skin with thick protective clothing. The manual method is recognized as the most effective. You can close the place where the plant grows with a dense black film and press it firmly to the ground. It is recommended to leave the film for at least a year.

Avoid seeding the plant, be sure to burn the umbrellas. Herbicides such as Roundup can be used. You can also treat the stump of a cut plant with vinegar essence (neatly) and put a tight plastic bag on top, then tie it.

Read also our article How to effectively deal with hogweed?

5. Canadian goldenrod

Canadian goldenrod ( Solidago canadensis ) was originally used as an ornamental, melliferous and medicinal plant. It was also used for tanning leather and dyeing fabrics. Later, it was found that goldenrod roots secrete substances that negatively affect other plants.

Canadian goldenrod (Solidago canadensis). © dogtooth77

Often grows on the site of spring fires and clearings. It spreads by cuttings and seeds. One of its inflorescences produces several tens of thousands of seeds with almost one hundred percent germination. It is recommended to mow the plant before flowering.

Displaces native plant species, creating overgrown patches. Not eaten by any farm animals other than sheep. Herbicide resistant. In America, it is a symbol of some states. Giant goldenrod (Solidago gigantea), which is very actively used in landscaping, is also an invasive species.

6. American maple

American maple or ash-leaved ( Acer negundo ) was brought to Russia about a hundred years ago. This plant is very easy to propagate by self-sowing. Unpretentious, drought-resistant, winter-hardy and able to grow even in places with high levels of radiation. Nothing grows after him or under his crown. In addition, these plants often fall during strong winds and cause man-made disasters.

American maple, or ash-leaved (Acer negundo). © CK Kelly

This species of maple was found in 34 regions of Russia. Its pollen can cause an allergic reaction (hay fever). The root system of this tree is capable of destroying the asphalt pavement. The leaves of the plant are poisonous to animals and other plants, even fallen ones.

Existing ornamental leafy forms with golden or variegated leaves are also dangerous. It actively propagates by seeds and root shoots, displacing other plants. Its leaves feed on a dangerous pest of garden plants - the American white butterfly.

Included in the Black Book of flora of central Russia. But at the same time, its unauthorized felling is prohibited, since in cities it belongs to the green spaces of the third category, and this can lead to administrative liability.

7. Red oak

Red oak ( Quercus rubra ) is an American species used for landscaping. Aggressively displaces the European oak, as it actively bears fruit annually. Designated as an invasive species in Ukraine and Belarus.

Red oak (Quercus rubra). © Sludge G

8. Multi-leaved lupine

Multi-leaved lupine multi-leaved (Lupinus polyphyllus) forms thickets that increase the nitrogen content of the soil as it is a nitrogen-fixing plant. But an excess of nitrogen in the soil is very harmful for myceliums of various types of fungi. Thus, the growth of lupine in the forest is detrimental to the harvest of mushrooms.

Multi-leaved lupine (Lupinus polyphyllus). © icnet

At the beginning of the 20th century, the plant was brought from North America as fodder and ornamental. And in the eighties of the last century, the formation of thickets of lupine in the fields and along highways was noted.

In defense of lupine, it can be said that it belongs to the "soft" invasive species, in addition, it can protect the garden plot from the mole cricket and cockchafer larvae. Lupins are well eaten by sheep.

9. Canadian small-flowered

Canadian small-flowered ( Erigeron canadensis ) is a field weed resistant to herbicides. Severely reduces soil fertility. Dry stems of this plant can damage the harvester in large quantities. And when the soil is clogged, it inhibits the growth of the vine growing next to it.

Erigeron canadensis. © Kevin Kenny

10. Iron Impatiens

Iron Impatiens ( Impatiens glandulifera ) is an annual plant, its height can reach 2.5 meters. Likes wet places, often spreads and forms huge thickets along rivers. Homeland is the Himalayas. For a long time it grew in our botanical gardens, was used as a honey plant and as an ornamental plant. In the middle of the 20th century, it began to actively propagate by self-seeding and aggressively capture new territories. It threatens the species diversity of native plants.

Iron Impatiens (Impatiens glandulifera). © Maja Dumat

11. Jerusalem artichoke

Tuberous sunflower or Jerusalem artichoke ( Helianthus tuberosus ) is able to form dense thickets. Unfortunately, it fell into the Black Book of the Moscow Region, as it is able to grow rapidly without control.

Tuberous sunflower, or Jerusalem artichoke (Helianthus tuberosus)

In his defense, it should be said that this plant is able to restrain and even oppress Sosnowsky's hogweed. It has a huge number of healing properties. Jerusalem artichoke stems are thorny and can damage the skin on contact.

12. Kudzu

Pueraria lobate, or Kudzu ( Pueraria montana var. lobata ) was brought to us from Asia. This vine, with missing supports, can even spread along the ground for a 30-meter length. Forms impenetrable overgrown areas in the Crimea.

Pueraria lobata, or Kudzu (Pueraria montana var. lobata). © Melissa McMasters

13. Fieldfare

Fieldfare ( Sorbaria sorbifolia ) is often used in landscaping, frost-resistant and undemanding. Easily propagated by cuttings and seeds. With uncontrolled resettlement, it can displace native plants, forming dense thickets.

Fieldfare (Sorbaria sorbifolia). © Fanghong

14. Reynoutria japonica

Reynoutria japonica ( Reynoutria japonica ) is not yet widely distributed. But the growth of this plant is capable of destroying the foundations of buildings and asphalt, so it is necessary to prevent its spread.

Reynoutria japonica, or Highlander Sakhalin (Reynoutria japonica). © Jay Pruett

15. White Poplar

White Poplar ( Populus alba ) used to be actively used in landscaping, as it grows quickly, and its foliage cleans the air well. Unfortunately, his down is an allergen. Therefore, planting new trees is not recommended today.

White poplar (Populus alba). © Andreas Rockstein

16. Cenchrus pauciflorus Benth

Cenchrus pauciflorus Benth is an annual weed from the grass family. Its spikelets are capable of damaging the oral cavity of farm animals with their prickly shell. In turn, these ulcerative lesions can lead to severe oral infections. Also, this weed plant harms pastures and crops. The plant is native to North America, has spread throughout the southern regions of Russia and is considered a dangerous quarantine species.

Cenchrus pauciflorus Benth. © Wayne Washam

17. Cocklebur

Cocklebur ( Cyclachaena xanthiifolia ) was brought to the Kyiv Botanical Garden in the 19th century from North America. At the moment, it is widely distributed in Ukraine, from where it also came to Russia. The pollen of this weed can cause symptoms of bronchial asthma.

Cocklebur cyclachena (Cyclachaena xanthiifolia). © Matt Lavin

18. Echinocystis lobata

Echinocystis lobata ( Echinocystis lobata ) is a vine that can suffocate a healthy tree in a couple of years.

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