I.W.M. – Integrated Weed Management
by Anna Wygrys, Galveston County Master Gardeners
Integrated Weed Management? Never heard of it? Integrated Weed Management is an international educational program researched, designed, implemented, and sponsored by agricultural universities and horticulture agencies promoting weed prevention and control.
IWM promotes a combination of various weed management practices to reduce a pest plant population to a tolerable level while preserving the quality of existing habitat, water and other natural resources. These balanced methods start with good weed prevention practices.
- Purchase good quality soil amendments. Do not purchase contaminated soil products from poorly maintained soil yards.
- When purchasing plants from commercial sources inspect the root ball. If possible remove the soil before planting. The alternative is to remove one inch of the top soil and one-half inch around the sides and bottom of the root ball. Many invasive weed seeds are notorious hitchhikers.
- Plan ahead and prepare new beds a month to six weeks prior to planting. Dig and turn the soil to a depth of approximately six inches exposing buried seeds that will sprout when exposed to light and moisture. Remove the new weed sprouts and repeat three or four times.
- Do not leave soil bare and open to the sun. Cover with newspaper, mulch or weed barrier to prevent germination of existing seeds or infestation from new sources. A cover crop helps to prevent weed invasions.
- Remove weed seedlings as soon as recognizable. Many weed species can bloom and set seed when very young.
- DO NOT ALLOW WEEDS TO MATURE AND BLOOM! Remember “one year of seeds equals seven years of weeds” because many weed seeds survive and are viable for years.
- Mulching is a good weed prevention practice. A layer of seven to ten sheets of newspaper topped by three to four inches of course mulch will significantly reduce weed germination and growth. Reapply mulch when it composts and deteriorates to a depth of one inch.
- Mow lawns regularly to prevent growth and reproduction of weed seeds. If there is a weed infestation, catch and dispose of the clippings.
- DO NOT COMPOST WEEDS! Weed seeds are tough – that is why they are a problem.
The number one weed problem in the world is Nut Sedge. Yellow Nutsedge, Cyperus esculentus, reproduces by seed, spreading roots, and underground nuts. The roots host bacteria which depletes soil nitrogen.
