What to do in the case of the invasion of slime mold

Suddenly, disgusting masses of a vomit-like substance appeared on a resident's compost pile and lawn, as well as under her shrubs. Unfortunately, when she brought in a sample of this gross matter to our Cooperative Extension office for identification, I opened the bag, and the stench was awful! I knew I had seen this substance before, but couldn't immediately remember the name.

This rotten-looking, smelly mess was a slime mold. Scientists argue whether this creature is fungal in nature or not. There are 700 species. Curtis Swift of Colorado State University Cooperative Extension describes its appearance as dog vomit. He says people have even taken their dogs to the veterinarian for diagnosis, thinking this foul substance was something their dog had vomited. Slime mold is actually quite an interesting organism, as it changes color and sometimes appears to be bubbling.

These organisms live in cool, shady, moist locations, such as on moist mulch and wet turf, or on logs in the forest. They can occur anywhere there is decaying material, such as leaves or wood. According to Swift, they feed on decaying matter, bacteria, protozoa and other minute creatures, which they engulf and digest. They have a creeping phase that dries into a hard structure, which produces clouds of spores that look like powdered dust. Wind, water and mowers can spread the spores. Once the spores reach cool, moist conditions, they start to grow.

Chemicals are ineffective controls and a waste of time and money. Since slime molds aren't usually a threat to plants or lawn, chemicals are not needed. Grass blades can sometimes yellow when the mold is present, but this is simply because the mold is preventing the sunlight from reaching the grass. Drying out the area reduces mold production. Loosening it up with a rake can also help. Washing the mass off turf and other areas will break up the colony of fungi. Or, if you are not squeamish, pick it up with a plastic bag and throw it away. Swift suggests enjoying the creatures' beauty! Now that's a plant pathologist talking.

For more information on slime mold, go to www.coopext.colostate.edu/TRA/PLANTS/slime.html

For more information on gardening in northern Nevada, contact me at (775) 887-2252 or skellyj@unce.unr.edu, or your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu. "Ask a Master Gardener" at mastergardeners@unce.unr.edu

n JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension.