Springtime invasives

22 Sunday Mar 2026

Tags

invasive plant, non-native invasive plant, Three-cornered leek, Allium triquetrum, Spanish bluebells, Hyacinthoides hispanica

Yes, the sight of a large field of flowering bluebells is the epitome of springtime but not when they are Spanish bluebells (Hyacinthoides hispanica), which are highly invasive non-native plants, and I do wish people in their home gardens and local authorities in public parks would stop their mass plantings of this species, especially if the area is near a woodland. As well as being invasive and out-competing native British bluebells, Spanish bluebells will also hybridise with them thus threatening the genetic integrity of the native species.

And the same goes for Three-cornered leeks (Allium triquetrum). They do look attractive, and many people who don’t know their plants well get one whiff of these plants and think they are Wild garlic (Allium ursinum), but Three-cornered leeks are another highly invasive non-native plant that will spread like wildfire if left unchecked. In fact, they are now such a problem that they are listed in Schedule 9 of the Wildlife and Countryside Act 1981, making it an offence to plant or cause them to grow in the wild.

Cotoneaster

10 Sunday Dec 2017

Posted by sconzani in nature, plants

≈ 17 Comments

Tags

Cotoneaster, invasive non-native, invasive plant

Am I the only person who used to pronounce this word wrongly: coton-easter instead of cot-own-e-aster?

cotoneaster (2)

Now that I’ve got the pronunciation right, I want to have a moan about the plant itself. Don’t get me wrong – with those charming, heart-shaped leaves and luscious red berries, it’s very attractive … when it’s in a garden. The problem is that birds find its berries luscious and attractive too, and they eat them, and they fly away, and they poop. And a few months later, up pops another Cotoneaster plant but not always where it’s wanted. (There are Cotoneaster plants by the score at Cosmeston Lakes Country Park, where I regularly go walking.)

So, now, because it has a habit of spreading easily, damaging native vegetation, and is difficult to get rid of, the Cotoneaster has been classified as a ‘non-native invasive’ on Schedule 9 of the Wildlife and Countryside Act in England and Wales making it an offence to plant or otherwise cause to grow these species in the wild. And it’s going to take a lot of back-breaking effort by someone to get rid of all the plants growing where they’re not wanted.

cotoneaster (4)

Horsetail: pretty, nasty

18 Monday Apr 2016

Posted by sconzani in nature, plants, spring

≈ 8 Comments

Tags

Equisetum arvense, Horsetail, invasive plant

Who would think such a pretty little plant could be considered a nasty invasive monster?

Horsetail Equisetum arvense (4)

Meet Equisetum arvense, more commonly known as Horsetail or sometimes Mare’s tail. My images show the plant in the springtime, when its sturdy shoots first push their way up through even the most compact ground (I’ve seen them force through a pile of tarmac left by workmen at the side of the road). These shoots grow between 20-50cm (10-20in) tall and that cone-like part at the top opens up to release spores, in a way similar to some fungi. In the summertime, the shoots develop into a miniature version of a fir tree plantation, their dense foliage growing to around 60cm (2ft) tall and crowding out other nearby plants.

Horsetail Equisetum arvense

The Horsetail’s roots are also strong, which is partly why it’s considered so invasive. The roots grow quickly and can dive down as deep as 2m (7ft) into the ground, so are difficult to remove, and they also spread sidewise. If this is growing in your neighbour’s garden, chances are it will soon appear in yours as well. I found whole banks of Horsetail growing along the water’s edge in Cardiff Bay, where it looked very pretty with the water sparkling in the background.

Horsetail Equisetum arvense (5)