Identification of Weeds & Methods of Weed Control - Basics of Gardening

A weed is a plant considered undesirable in a particular situation, such as a plant in the wrong place. Weeds can compete with desired plants for water, nutrients, and sunlight, and interfere with harvesting or reduce crop quality.

There are two types of annual weeds. Summer annual weeds emerge as soon as soil temperatures warm in the spring or early summer and continue to germinate throughout the summer. Winter annuals germinate from seed in the last summer or early fall, live through the winter, flower and set seeds, and die out the following summer.

A perennial weed is a plant that lives for many years and does not die after flowering. Perennial weeds have underground parts that store food over the winter and allow them to reemerge in the spring.

Some methods of weed control include hand-pulling for perennial weeds, herbicide application for effective and selective weed control, physical or mechanical control through pulling, digging, disking, blowing, and mowing, cultural control by establishing competitive and desired vegetation to prevent or slow down weed invasion, and biological control using living agents such as insects, bacteria, fungus, or grazing animals to suppress weed vigor and spread.

The goal of biological control is not eradication but the use of living agents to suppress weed vigor and spread. These agents can be insects, bacteria, fungi, or grazing animals like sheep, goats, or horses. Biological control can produce results similar to manual or mechanical methods of weed management.