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How to Manage Pests

UC Pest Management Guidelines


Weeds growing in and around drip irrigated potted geraniums.

Floriculture and Ornamental Nurseries

Weed Classifications

(Reviewed 7/00, updated 7/00)

In this Guideline: More about weeds in loriculture and ornamental nurseries:

Weeds can be divided into broadleaf plants (dicotyledons) or narrowleaf plants (monocotyledons). Most narrowleaf plants are grasses, but this group also includes sedges, which are important weeds. Another way to identify weeds is by when they germinate and grow (Table 1). Many common weed species are winter annuals, germinating mainly in fall and grow through winter and spring. Summer annuals germinate in spring and grow through summer. A few weeds complete a life cycle in 2 years and are referred to as biennials (e.g., bristly oxtongue). Some of the worst of the weed species (e.g., bermudagrass) are perennials; they live for 2 years or more.

TABLE 1. Common Weeds in Floriculture and Ornamental Nurseries.

Common NameScientific Name

WINTER ANNUALS 
bittercress, lesser-seededCardamine sp.
bluegrass, annualPoa annua
burclover, CaliforniaMedicago polymorpha
chickweed, commonStellaria media
cudweedsGnaphalium spp.
filareesErodium spp.
goosefoot, nettleleafChenopodium murale
groundsel, commonSenecio vulgaris
lettuce, pricklyLactuca serriola
mallow, little (cheeseweed)Malva parviflora
mustard, wildBrassica sp.
nettle, stingingUrtica dioica
pearlwortSagina sp.
radish, wildRaphanus raphanistrum
rocket, LondonSisymbrium irio
shepherd's-purseCapsella bursa-pastoris
sowthistle, commonSonchus oleraceus
spurry, cornSpergula arvensis
willowherbsEpilobium spp.
 
SUMMER ANNUALS 
barnyardgrassEchinochloa crus-galli
buttercup, yellowRanunculus sp.
crabgrassesDigitaria spp.
fleabaneConyza sp.
henbitLamium amplexicaule
horseweedConyza canadensis
junglericeEchinochloa colona
lambsquartersChenopodium album
nightshade, blackSolanum nigrum
nightshade, hairySolanum sarrachoides
pigweed, prostrateAmaranthus blitoides
pigweed, roughAmaranthus sp.
pigweed, tumbleAmaranthus albus
puncturevineTribulus terrestris
purslane, commonPortulaca oleracea
sprangletopsLeptochloa spp.
spurge, prostrateChamaesyce humistrata
 
COMMON BIENNIALS AND PERENNIALS
bermudagrassCynodon dactylon
bindweed, fieldConvolvulus arvensis
johnsongrassSorghum halepense
nutsedge, purpleCyperus rotundus
nutsedge, yellowCyperus esculentus
oxtongue, bristly (biennial)Picris echioides
woodsorrel, creepingOxalis corniculata

Growing site and production practices largely determine which weeds are likely to become problems at a site. For example, weeds commonly associated with container nursery production include creeping woodsorrel, common groundsel, lesser-seeded bittercress, and prostrate spurge. Sometimes pearlwort, annual bluegrass, or willowherb are a problem. In field sites, weed species vary greatly but the weed spectrum can be influenced by management practices in the field and by the environment. Because of these variations, each type of production situation is addressed separately in this guideline. After a section on general methods of weed management, there are special sections for weed management in:

  • container nurseries,
  • field-grown trees and shrubs,
  • field-grown flowers, and
  • greenhouse-grown crops.

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Floriculture and Ornamental Nurseries
UC ANR Publication 3392
Weeds
C. L. Elmore, Weed Science/Vegetable Crops, UC Davis
C. A. Wilen, UC IPM Program, UC Cooperative Extension, San Diego Co.

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Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2005 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/r280700999.html revised: May 20, 2005. Contact webmaster.