Ideas for Getting a Firm Grip on Weed Control

25 July 2011

Farmworkers weed strawberry rows on a field outside Salinas, California

This is the VOA Special English Agriculture Report.

Weeds compete with plantings for water and nutrients. So farmers and gardeners may have good reason to hate them. But weeds can also bring pretty flowers and wild beauty to places lacking either. British nature writer Richard Mabey offers support for weeds in his new book. The title says it all: "Weeds: In Defense of Nature's Most Unloved Plants."

But when exactly is a plant considered a weed? Experts at Penn State University say the answer is simple: when the undesirable qualities outweigh the good qualities.

A crop plant generally produces several hundred seeds. But a weed plant can produce tens or even hundreds of thousands of seeds. And if seeds get buried, they may survive for many years underground.

Eradicating weeds means that you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land.

A more common way to deal with weeds is to control them enough so that the land can be used for planting. Experts advise using two or more control methods to deal with weeds.

Chemical weed killers or natural treatments like corn gluten can suppress weed growth. But so can dense planting. Bill Curran is a professor of weed science at Penn State. He says a dense, competitive crop that quickly shades the soil from the sun will help reduce weed growth.