6 Sustainable natural weed control and cultivation What is a weed? The generally accepted definition of a weed is any plant that, for some reason or other, is unwanted in a particular position. Any type of plant has the potential to be a weed. Common reasons why people do not want species to grow include | .6 Sustainable natural weed control and cultivation What is a weed The generally accepted definition of a weed is any plant that for some reason or other is unwanted in a particular position. Any type of plant has the potential to be a weed. Common reasons why people do not want species to grow include Competition - weeds can compete with your desired plants for space light nutrients and moisture Safety - some plants may be poisonous or cause allergies eg St John s wort bathurst burr parthenium weed others may have spines or spikes eg giant devil s fig currant bush and Chinese apple or sharp grass seeds that can injure animals and humans eg spear grass Harbouring or hosting pests and diseases - some plants may act as hosts or as attractants to pests or diseases while others may provide a safe haven for pests such as rabbits and foxes Tainting - some weeds eg capeweed wild garlic can taint the taste of meat and milk from animals such as cattle sheep goats and pigs Contamination - plant parts particularly seeds can get caught up in clothing or can contaminate produce such as grains or get entangled in animal fur or fleece or fibre crops eg cotton or in hay Interfere with cultivation - some plants can become entangled in machinery making tasks such as cultivation mowing or machine harvesting difficult and possibly damaging machinery Soil erosion - some weeds are very competitive and will easily shade out other more desirable plants if the weed is only seasonal eg an annual or dies back during winter it may leave exposed soil that may be easily eroded Aesthetics - some plants may be weeds simply because they look bad or they have offensive odours 102 Sustainable Agriculture Environmental - these are plants that invade native vegetation displacing the indigenous species they can severely affect local flora and fauna populations eg lantana camphor laurel Singapore daisy and water hyacinth . Controlling weeds Once it is determined that a particular plant or group of .
