Horticultural codes of practice in the United Kingdom
In the United Kingdom, horticultural codes of practice have been elaborated by the Scottish Executive, the Department of Food and Rural Affairs (DEFRA), the Welsh Assembly Government, “gardening Which?”, the garden centres Association, the Horticultural Trades association, the Royal Horticultural Society, the National Trust, the ornamental and Aquatic Trades Association, Plantlife International and the Royal Botanic gardens (Kew).
These codes are voluntary and give guidance on the safe use, control and disposal of invasive non-native plants. They apply to everyone involved in horticulture or any other activities related to the use of plants in the United Kingdom. The aims of these codes are to promote compliance with legislation and to prevent the spread of invasive non-native species across the countryside. The following advice is addressed to the various plant users:
Know what you are growing: to all users
When in doubt about the invasiveness potential of a non-native plant, it is good practice to take a precautionary approach. It is also worth giving careful consideration to the invasive characteristics of a plant when exchanging it with friends or growing it from imported seeds.
Beware of hitch-hiking pests on plants and in soil: to importers/buyers (nurseries, superstores, garden centres, botanic collections, aquarists)
Plant Health regulations relate to pathogens and pests but not to potentially invasive plants or seeds that are transported unintentionally. It is therefore good practice to keep imported plant material isolated from locally produced plants and from those growing in the wild.
Topsoil should be free of weeds and all viable propagules of invasive non-native species (rhizomes, seeds, corms, etc.).
Know what you are supplying/selling: to suppliers/retailers (nurseries, superstores, aquarists)
Avoid selling non-native plants that are known to be invasive.
Label plants clearly and accurately: to suppliers/retailers (horticulturalists, nurseries, garden centres, aquarists, voluntary organizations)
Know what you are recommending: to landscape architects, garden designers, design engineers, tutors, authors and publishers of gardening books
Be aware of the plants that are considered invasive and do not recommend invasive non-native plants to be planted. Always use the correct Latin name, consider revising or withdrawing old publications encouraging the use of invasive plants.
Dispose of plant wastes responsibly: to all users
Plant material should never be disposed of in the countryside or even over the garden fence; much can be composted or taken to recycling centres. Some weeds should not be composted, as composting will not destroy the plant (ex. Reynoutria japonica).
Take advice on best control techniques: to all users
Invasive plants are difficult to control but timely action will reduce the scale of the task. For plants with strong rhizomes, use root barrier fabrics to contain their spread.
Be aware of relevant legislation: all users
Legislation regarding non-native plants and their safe control and disposal should be followed at all times.
Control invasive non-native plants safely: all users (gardeners, landscape architects, garden contractors, local authorities)
DEFRA Website - Helping to prevent the spread of invasive non-native species - Horticultural code of practice. http://www.defra.gov.uk/wildlife-countryside/non-native/non-native_old/pdf/non-nativecop.pdf