ABSTRACT
An ephemeral weed is a weed that has several life cycles in a growing season. An annual weed is a weed that completes its life cycle in a growing season. A perennial weed is a weed that lives through several growing seasons. Perennial weeds such as couch, docks, plantains, bindweed and Japanese knotweed have long-lived underground systems that are difficult to control. The large quantities of food stored in these vegetative organs enable these species to emerge quickly from the soil in spring, often from considerable depths if they have been ploughed in. A total, translocated herbicide such as glyphosate, sprayed onto couch in fallow soils during active weed vegetative growth, kills most of the underground rhizomes. The roots of field bindweed are also deep-rooted, with rhizomes arising from the roots. Growth outwards by 2 m may be achieved each year. Field bindweed produces many seeds that can survive in the soil for several years.
