Weed management in annual color beds

Department of Horticultural Science Horticulture Information Leaflet 8644 Revised 12/98 - Author Reviewed 12/98 WEED MANAGEMENT IN ANNUAL COLOR BEDS Joseph C. Neal, Extension Specialist, Weed Management Stuart L. Warren, Professor of Horticultural Science Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating. Weeds compete with ornamental plants for water, light, and nutrients, reducing aesthetic quality and plant growth. To minimize these problems, a weed management program should be developed and implemented prior to planting. A successful weed management program involves four steps: • U nderstanding weeds (identification and lifecycle) • Understanding the available weed management options. • Site preparation -eliminate perennial broadleaf weeds and sedges before planting • Implementinga combination of effective methods to prevent and control weeds Understanding Weeds The first step in developing a successful weed management program is identifying your weeds and their associated life cycle. Knowing the correct name helps to understand the herbicide labels and control recommendations. Several pictorial guides are available for identifying weeds (refer to suggested references). Most weeds found in color beds have one of three lifecycles: summer annuals, winter annuals, and perennials. The weed's life cycle provides information on timing of germination and method of reproduction. Summerannual weeds germinate in the spring (beginning with dogwood bloom) and continue throughout thesummermonths. They flower and produce seed prior to the first frost. Common summerannual weeds include grasses such as bamyardgrass, crabgrass, and goosegrass; and broadleaves such as annual lespedeza, caipetweed, common purslane, morningg lories, pigweed and prostrate spurge. Winter annual weeds germinate in late summer and early fall, overwinter as small dormant but green plants, and flower and produce seed in late winter and early spring. Winter annual weeds die with the onsetof warm weather usually in late spring to early summer. Common winter annual weeds include annual bluegrass, annual sowthistle, common chickweed, hairy bittercress, henbit, horse weed and short buttercup. Perennials weeds are classified according to their method of reproduct ion as creeping or simple. Creeping perennials reproduce by above ground stems (stolons) or below ground stems (rhizomes). Of course, most perennial weeds can also reproduce by seed. Examples include nutsedge, bermudagrass, red sorrel, bindweed, groundivy, and quackgrass. Simple perennials spread by seed, they have no natural means of spreading vegetatively (stolonsorrhizomes). Their roots are usually fleshy and can grow very large. Examples include common dandelion, curly dock, buckhom and broadleaf plantain, and pokeweed. It is important to scout the weed population throughout the year to assess the success of the weed management program. North Carolina Cooperative Extension Service NORTH CAROLINA STATE UNIVERSITY COLLEGE OF AGRICULTURE & LIFE SCIENCES