louisiana yards and neighborhoods weed management

Louisiana Yards and Neighborhoods


Weed ManagementWeed Management

www.lsuagcenter.com/lyn

WeedsWeeds

• Plants growing out of place

• Compete with lawns and landscape

• Water • Nutrients • Light

• Plants growing out of place

• Compete with lawns and landscape

• Water • Nutrients • Light

DandelionDandelion

ThistleThistle

Common chickweedCommon chickweed

Types of Weeds Types of Weeds • Broadleaves

– Netted veination

– 2 cotyledons

– Taproot

– Showy flowers

• Grasses

– Parallel

– 1 cotyledon

– Fibrous roots

• Sedges

– “Nutgrass”

– Triangular stems

– Leaves in 3s

• Broadleaves

– Netted veination

– 2 cotyledons

– Taproot

– Showy flowers

• Grasses

– Parallel

– 1 cotyledon

– Fibrous roots

• Sedges

– “Nutgrass”

– Triangular stems

– Leaves in 3s

White cloverWhite clover

DallisgrassDallisgrass

Purple nutsedgePurple nutsedge

Why So Many Weeds?Seed Production

Why So Many Weeds?Seed Production

• Pigweed – annual broadleaf• 13,000 – 100,000 seeds/year• Dormancy – survive 30 years• Don’t allow seed production

• Pigweed – annual broadleaf• 13,000 – 100,000 seeds/year• Dormancy – survive 30 years• Don’t allow seed production

PigweedPigweed Pigweed - heavy seed producer Pigweed - heavy seed producer

How Do Weeds Spread?How Do Weeds Spread?

1) Nature• Animals and birds• Winds – dandelion• Rains and flooding• Some type of runner – rhizome, stolon

2) Humans• Impure seed/sod• Compost and mulch• Machinery – contaminated mowing equipment• Contaminated soil

1) Nature• Animals and birds• Winds – dandelion• Rains and flooding• Some type of runner – rhizome, stolon

2) Humans• Impure seed/sod• Compost and mulch• Machinery – contaminated mowing equipment• Contaminated soil

Weeds in Lawns & LandscapeWeeds in Lawns & Landscape

• Host for diseases

• Insects

• May cause allergies in humans

• Host for diseases

• Insects

• May cause allergies in humans

Poison ivyPoison ivy

Indicator WeedsIndicator Weeds

Soil condition• Soil compaction• Low nitrogen• Poor drainage

Soil condition• Soil compaction• Low nitrogen• Poor drainage

Indicator weeds• Goosegrass, annual

bluegrass• Clovers• Dollarweed, sedges,

doveweed

Indicator weeds• Goosegrass, annual

bluegrass• Clovers• Dollarweed, sedges,

doveweed

Annual bluegrassAnnual

bluegrass White cloverWhite clover DollarweedDollarweed DoveweedDoveweed

Cultural Practices That Improve Turf & Ornamentals

Cultural Practices That Improve Turf & Ornamentals

Discourage competition from weeds

Discourage competition from weeds

Virginia ButtonweedVirginia Buttonweed

• #1 weed in lawns

• Perennial

• Common in lawns mowed too low

• Highly drought-tolerant

• Reproduces by seed, stem fragments, etc.

• #1 weed in lawns

• Perennial

• Common in lawns mowed too low

• Highly drought-tolerant

• Reproduces by seed, stem fragments, etc.

DallisgrassDallisgrass• Perennial - stubby

rhizomes

• Common throughout the South

• Tolerates low mowing and drought

• More cold-tolerant than lawn grasses

• Perennial - stubby rhizomes

• Common throughout the South

• Tolerates low mowing and drought

• More cold-tolerant than lawn grasses

ChamberbitterChamberbitter

• Summer annual

• Reproduces by seed

• Each fruit contain 6 seeds

• Quite common in flower beds

• Summer annual

• Reproduces by seed

• Each fruit contain 6 seeds

• Quite common in flower beds

DollarweedDollarweed

• Perennial

• Reproduces by seed and rhizomes

• Common in wet areas

• Infests thin lawns

• Perennial

• Reproduces by seed and rhizomes

• Common in wet areas

• Infests thin lawns

Florida BetonyFlorida Betony• Perennial plant

• Very invasive weed in landscapes

• Square stem

• White to pink flowers

• Reproduces quickly by tubers and seeds

• Perennial plant

• Very invasive weed in landscapes

• Square stem

• White to pink flowers

• Reproduces quickly by tubers and seeds


• Proper lawn and landscape cultural practices first

• Identify weeds

• Calibrate sprayers and spreaders

• Read and understand herbicide labels

• Proper lawn and landscape cultural practices first

• Identify weeds

• Calibrate sprayers and spreaders

• Read and understand herbicide labels




www.lsuagcenter.com/lyn

louisiana yards and neighborhoods weed management

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