News You Can Use Distributed 04/02/08
If springtime brings mild weather and an extended wet period, watch for a sinister-looking fungus or slime attacking your lawn.
Slime molds, which appropriately describe these primative fungi, cover the turf leaves with a dusty-gray, black mass, according to LSU AgCenter horticulturist Dr. Tom Koske.
When you look closely, you can see tiny, round balls scattered over the foliage. If you rub this dusty coating between your fingers, a sooty-like powder covers them. This sooty-like powder is the reproductive spores of these primitive fungi, Koske explains.
This slime mold is one of the Myxomycetes group composed of five genera and about 100 species.
Slime molds normally live unseen in the soil where they feed on thatch and decaying organic matter. They do not feed on living plants; they only use the foliage for support during reproduction and dispersal. The damage to turf and other plants is only from being shaded from sunlight. Shading may cause the leaf blades to temporarily turn yellow. The black powder also gets on shoes, dogs and kids, but it will wash off.
Slime mold also can occur in late fall if the weather again is mild and wet. It disappears rapidly as soon as the air becomes dry. Control is usually not necessary, Koske says, explaining that you can break up the masses by mowing, sweeping with a broom or by spraying with a strong stream of water.
The horticulturist cautions, however, to avoid hosing off affected areas during prolonged damp weather because doing so may spread the mold rather than wash it away. You can apply a garden turf fungicide to affected areas if desired.
For more on slime molds, go to www.lsuagcenter.com and search “slime mold crust.”
For related gardening and landscape information, click on the Lawn and Garden link at the LSU AgCenter Web site, www.lsuagcenter.com. Also, contact the county agent in your local parish LSU AgCenter office.
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On the Internet: LSU AgCenter: www.lsuagcenter.com
Contact: Tom Koske (225) 578-2222 or tkoske@agcenter.lsu.edu
Editor: Mark Claesgens (225) 578-2939 or mclaesgens@agcenter.lsu.edu