Schedule 9 invasive plants and development

Schedule 9 plants are invasive and generally need controlling on a development site. After talking to a client about yellow archangel, we thought a list of schedule 9 would be helpful. It is an offence to “plant or otherwise cause to grow in the wild invasive non-native plants listed on Schedule 9 of the Wildlife and Countryside Act.”

A lot of the most invasive are aquatic or live in marshy environments e.g. Crassula helmsii, but brownfield sites also harbour species such as knotweed.  We can advise on control methods to incorporate into construction management for you.

Plants listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales

Common Name Latin Name  
Elodea (waterweeds) eg Canadian waterweed Elodea Canadensis All species of the Elodea genus Aquatic – widespread in Norfolk
Curly waterweed Lagarosiphon major Aquatic
Duck potato Sagittaria latifolia Aquatic
Entire-leaved cotoneaster Cotoneaster integrifolius Garden escape
Knotweed Fallopia japonica x Fallopia sachalinensis (a hybrid knotweed) Brownfield sites
False Virginia creeper Parthenocissus inserta Garden escape
Fanwort (Carolina water-shield) Cabomba caroliniana Aquatic
Few-flowered leek Allium paradoxum
Floating pennywort Hydrocotyle ranunculoides Aquatic – highly invasive
Floating water primrose Ludwigia peploides Aquatic
Giant hogweed Heracleum mantegazzianum Fairly commonly encountered
Giant knotweed Fallopia sachalinensis Brownfield sites
Giant rhubarb Gunnera tinctoria Too cold in Norfolk
Giant salvinia Salvinia molesta Aquatic
Green seafingers Codium fragile
Himalayan cotoneaster Cotoneaster simonsii
Hollyberry cotoneaster Cotoneaster bullatus
Hottentot-fig Carpobrotus edulis Too cold in Norfolk
Indian balsam Himalayan balsam Impatiens glandulifera Water courses and rivers
Japanese knotweed Fallopia japonica Brownfield sites
Japanese rose Rosa rugosa
Montbretia Crocosmia x crocosmiiflora
New Zealand pigmyweed (Australian swamp-stonecrop) Crassula helmsii Aquatic – highly invasive in Norfolk
Parrot’s-feather Myriophyllum aquaticum Aquatic
Perfoliate Alexanders Smyrnium perfoliatum
Purple dewplant Disphyma crassifolium
Red algae Grateloupia luxurians
Rhododendron Rhododendron ponticum Acid soils only
Rhododendron Rhododendron ponticum x Rhododendron maximum Acid soils only
Small-leaved cotoneaster Cotoneaster microphyllus Garden escape
Shallon Gaultheria shallon
Three-cornered garlic Allium triquetrum Too cold in Norfolk ?
Variegated yellow archangel Lamiastrum galeobdolon subsp. argentatum Garden escape
Virginia creeper Parthenocissus quinquefolia Garden escape
Water fern Azolla filiculoides Aquatic
Water hyacinth Eichhornia crassipes Aquatic
Water lettuce Pistia stratiotes Aquatic
Water primrose Ludwigia grandiflora / Ludwigia uruguayensis Aquatic
Yellow azalea Rhododendron luteum Acid soils only

Invasive Non-Native Species – Japanese Knotweed – successful control

Our team are trained to recognise Invasive Non-Native Species [ also called INNS ]  on survey sites and advise on issues with their control.

One of the most pernicious, we encounter is Japanese Knotweed, which is an Asian species originating as a garden escape, spread via root fragments of its rhizomes, often from fly tipping or contaminated topsoil. Once established the underground rhizomes, Continue reading