Louisiana Yards and Neighborhoods www lsuagcenter comlyn Weed

Louisiana Yards and Neighborhoods www. lsuagcenter. com/lyn Weed Management

Weeds • Plants growing out of place • Compete with lawns and landscape • Water • Nutrients • Light Common chickweed Thistle Dandelion

Types of Weeds • Broadleaves – Netted veination – 2 cotyledons – Taproot – Showy flowers White clover • Grasses – Parallel – 1 cotyledon – Fibrous roots Dallisgrass • Sedges – “Nutgrass” – Triangular stems – Leaves in 3 s Purple nutsedge

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 - heavy seed producer

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

Weeds in Lawns & Landscape • Host for diseases • Insects Poison ivy • May cause allergies in humans

Indicator Weeds Soil condition • Soil compaction • Low nitrogen • Poor drainage Annual bluegrass White clover Indicator weeds • Goosegrass, annual bluegrass • Clovers • Dollarweed, sedges, doveweed Dollarweed Doveweed

Cultural Practices That Improve Turf & Ornamentals Discourage competition from weeds

Virginia Buttonweed • #1 weed in lawns • Perennial • Common in lawns mowed too low • Highly drought-tolerant • Reproduces by seed, stem fragments, etc.

Dallisgrass • Perennial - stubby rhizomes • Common throughout the South • Tolerates low mowing and drought • More cold-tolerant than lawn grasses

Chamberbitter • Summer annual • Reproduces by seed • Each fruit contain 6 seeds • Quite common in flower beds

Dollarweed • Perennial • Reproduces by seed and rhizomes • Common in wet areas • Infests thin lawns

Florida Betony • Perennial plant • Very invasive weed in landscapes • Square stem • White to pink flowers • Reproduces quickly by tubers and seeds

Weed Management • Proper lawn and landscape cultural practices first • Identify weeds • Calibrate sprayers and spreaders • Read and understand herbicide labels

Louisiana Yards and Neighborhoods www. lsuagcenter. com/lyn Weed Management