Chemically-conscious gardeners use bugs to beat back the weeds

Organic gardeners can control pesky weeds with the help of some common soil microbes, according to an article in the May 2005 issue of Microbiology Today, the quarterly magazine of the Society for General Microbiology.

As Robert J. Kremer of the University of Missouri explains, soil that suppresses the growth of weeds isn’t science fiction and doesn’t involve chemical fertilisers and herbicides. “Weeds have been a nuisance for gardeners since ancient times,” says Professor Kremer. “And we often rely on the convenience of herbicides to help remove them.”

Use of chemical herbicides and fertilisers can lead to contamination of the environment, as well as resistant pests. So reducing or eliminating the use of these petroleum-based products is very important.

Professor Kremer’s research shows how well-managed microbes can provide an effective, alternative means of weed control. “The community of soil microbes is vast and using fairly simple techniques we can select the segments of this community that aggressively attack weed seeds or infect weed seedlings,” explains Professor Kremer.

Simple measures such as adding organic composts and growing winter-hardy soil covers, such as vetch, increases the number of weed-stopping microbes and have been found not only to reduce the effort of weeding and the use of chemical weed killers, but to also condition many soils that are in poor shape, restoring the quality and productivity of the land.

Britain is a nation of gardeners, apparently, but I wonder if even the gardening guru Alan Titchmarsh knows all that is going on invisibly in his back yard. This issue of Microbiology Today focuses on microbes in the garden. Pick up a free copy of the magazine at the RHS Chelsea Flower Show 2005 from the Society’s stand in the Floral Marquee.

Other features in the May 2005 issue of Microbiology Today include:

· The threads that bind: symbiotic fungi in the garden (page 56)
· Bacterial and fungal diseases of garden plants (page 60)
· ‘Broken’ tulips and tulip breaking virus (page 68)
· Barbecue roulette (page 72)
· Bugs within bugs: symbiotic bacteria in garden insects (page 76)
· Home composting and its role in waste management (page 80)
· Comment: Plant pathogens on the move (page 100)

These are just some of the articles that appear, together with all the regular features and reports of Society activities.