After habitat destruction, invasive non-native species such as Japanese knotweed are the most serious threat to global biodiversity. Despite the lockdown, all of these invasive weeds have been growing strongly this summer - but it's not all about knotweed!
Giant Hogweed & Other Highly Invasive Plants
Our gardens have been greatly enriched by the introduction of plants from abroad but a small number (such as Giant Hogweed and Horsetail for example) have proved highly invasive in the UK, threatening natural habitats and native species. The control of these species is difficult and costly, yet many are widely available with little indication of the damage they can do if they are allowed to escape from gardens or are disposed of carelessly.
Invasive Species - EU Regulations
The EU Regulation on Invasive Alien plants, which became law early in 2015 and has had several updates since, has a provision for a list of species of EU-wide concern. Species that are included on the list attract the strictest measures of control, including a ban on keeping, growing or cultivating, transporting or trading, use or exchange, as well as release into the wider environment. These controls apply to individuals as well as organisations and businesses that own or hold any of these species.
Below are the 36 plants on the list which are banned from sale:
- Acacia saligna (golden wreath wattle)
- Ailanthus altissima (tree of heaven)
- Andropogon virginicus (broomsedge)
- Asclepias syriaca (milkweed)
- Baccharis halmifolia (tree groundsel)
- Cabomba caroliniana (Carolina fanwort)
- Cardiospermum grandiflorum (balloon vine)
- Cortaderia jubata (purple pampas grass) Ehrharta calycina (purple veldgrass)
- Eichhornia crassipes (water hyacinth)
- Elodea nuttallii (Nuttall’s water weed)
- Gunnera tinctoria (Chilean rhubarb)
- Gymnocoronis spilanthoides (Senegal tea)
- Impatiens glandulifera (Himalayan balsam)
- Lagarosiphon major (curly waterweed)
- Lespedeza cuneata (Chinese shrub clover)
- Ludwigia grandiflora (water primrose)
- Ludwigia peploides (water primrose)
- Lygodium japonicum (climbing fern)
- Heracleum mantegazzianum (giant hogweed)
- Heracleum persicum (giant hogweed, Tromsø palm)
- Heracleum sosnowskyi (giant hogweed)
- Humulus scandens (Japanese hop)
- Hydrocotyle ranunculoides (floating pennywort)
- Lysichiton americanus (American skunk cabbage)
- Microstegium vimineum (Japanese stiltgrass)
- Myriophyllum aquaticum (parrot’s feather)
- Myriophyllum heterophyllum (broadleaf watermilfoil)
- Parthenium hysterophorus (parthenium weed)
- Pennisetum setaceum (crimson fountain grass)
- Persicaria perfoliata (Asiatic tearthumb) Prosopis juliflora (mesquite)
- Pueraria montana var. lobata (kudzu)Salvinia molesta (giant salvinia)
- Triadica sebifera (Chinese tallow tree)
Land Owner ResponsibilityGardeners who already have these species in their gardens are not likely to be prosecuted for having them, but will be required to meet the other provisions of the Regulation to ensure that they control the species effectively on their property and do not allow it to spread. If at all possible they should seek to remove the invasive plants altogether. Gardeners will be expected to dispose of listed plant material by burning, burial or in the green waste recycling, as appropriate.
As the EU Regulation has been transposed into UK law, it continues to be effective following the UK’s leaving the European Union, although it is unclear at the present time whether any future additions to the list of species of concern will be adopted in the UK.
Invasive Plant Specialists
At TCM, we contend with all kinds of invasive plants, and something they all have in common is that they’re best tackled early. So, if you’re not sure what you’re dealing with, give us a call on 0330 6781077, or email us via our contact form.