Invasive plants – What should you do?

Invasive plants – What should you do?

Imagine taking a stroll along the local footbath or riverbank during summer. You might see large leaves with plumes of cream flowers, purple blossoms with an appley smell, or huge lacy white flowers. Each summer brings new horror stories about these biodiversity-bashing bullying bullies, particularly knotweed.

Alien plants are coming to areas, taking nutrients, confusing pollinators, and destroying biodiversity. It’s the stuff that makes nightmares. Time to take back control. Predictably, the truth is less alarmist.

  • However, “Native” does not necessarily mean beneficial. Many native things are highly invasive. It’s like bracken, which has taken over the majority of the uplands. You can also have monocultures, which are heather plants that cover the entire surface of the earth, and are artificially maintained by grouse moorland owners.
  • However, there are real problems when an alien plant is too successful. Anything really plentiful creates the seeds for instability.
  • Non-native plants are very effective at outrunning native flora. One is destructive and the other is dangerous to humans. You’re not permitted to plant, grow, or allow them to spread to the wild.

What should you do if you find an invasive species in your yard?

Don’t give it away. If it is doing well, don’t give it away to others – there’s a tradition among gardeners that you share plants, but these things are not something you should be sharing. Fly-tipping can lead to widespread spread. They should not be moved. Instead, they should be burned or composted.

  • Gardeners should also be on the lookout for potential triffids. They are the best people to tell when a non-native is becoming a problem. This is the idea behind Plant Alert.
  • Tetrapanax, an attractive and jungly-looking rice paper plant. Although it was probably just observing its borders, it is now being found wild. It was terrible how it can spread.

Can we beat invasives?

Sooner than later their natural enemies catch them up with: Nature abhors monoculture. But the question is whether we should intervene before they do. One avenue of research is to introduce a natural predator. The “Biological Control” research using fungi and other insects is ongoing with different degrees of success.

There’s also the big planetary unknown. We don’t know what impact climate change might make. Plants might behave differently due to warmer winters. While we await to find out what the future leafy overlords have in store for us, here are the most dangerous bullies to watch.

  • Japanese knotweed is the plant that everyone fears. It can cause a denial of your mortgage offer and even grow through concrete years later than you thought.
    • The visible parts – the bamboo-like stems and feathery cream flowers – can grow to 2-3m.
    • But, more important, the root system can stay dormant for as long as 20 years before it springs back into life, possibly through your foundations.
  • Asbestos is the most dangerous substance in the plant world. But is this really a problem? It is not an ecological problem, but an economic one.
  • Given the places it grows, which are mostly abandoned sites, Japanese knotweed is very rare. All you have to do is cut it every five years for five years, and it will eventually die.
  • Cow parsley is a popular crop for Etsy sellers and Instagram posters.
  • Furocoumarin, a compound found in giant hogweed sap, makes skin extremely photosensitive. This can lead to severe burns and blisters if it is touched. These effects can last for months or even years.
    • Giant hogweed is a plant that originated in the Caucuses. It was introduced to the UK in mid-19th century. It is a very bad plant that must be eradicated.
  • Bright, large, and beautiful, Himalayan balsam is a problem for riverbanks. Grows very rapidly, doesn’t require much in the way of water and nutrients, and can get up over all our native plants to shade them out.
  • Himalayan balsam, like most invasive problems, creates monocultures that outcompete other plants. It also dies to nothing each year, “leaving bare ground along the riverbanks that could get eroded away.” Clearance can be tricky.
    • While people may know it’s bad news and want to remove it, they could end up doing more harm than good. It’s usually safe to cut or uproot from May through July.
    • However, once the seed heads have ripened, it’s best to leave the job to professionals. Roots left on the soil can become rerooted if they aren’t broken up.

What’s so special about purple flowers?

Rhododendron, an 18th-century imported Rhododendron, thrives in eco-delicate and valuable environments that support many species. It spreads quickly, reaching 8m in height and shading out or smothering low-lying vegetation. It is an interesting example of our ambivalence towards invasive species. People say it’s really nice when it’s in bloom. This is because we might have visited plantations before realizing how dangerous it can be.

Aquatic plants pose a particular problem when they become invasive. You can’t use herbicides because they break down and multiply, and the shoots then grow new plants. This dense carpet excludes other plants and causes habitat damage.