Contact Us
University of California Cooperative Extension Ventura County
669 County Square Drive, Suite 100
Ventura, CA 93003
Phone: 805.645.1451
Fax: 805.645.1474
Office Hours:
Monday - Friday from 9 a.m. to 4 p.m.
The office will be closed for the following holidays:
December 24-25 - Christmas Holiday
December 31 - January 1 - New Year Holiday
January 20 - MLK Day
Mosses, Alga and Slime Molds
In a shaded, moist area the most likely organisms you might encounter are mosses, alga or slime molds. Mosses are green, and the plant has some identifiable structure. Alga species come in many colors from black to gray to green to yellow or red. Some algae look like velvet, while others appear as an amorphous, slimy, shiny mass. Slime molds are usually very periodic in their appearance, being visible for a short time a few times per year. Usually, all these plants are found where there is more or less continuous moisture, shady conditions, and poor (low nutrient) soils. Fortunately, all three of these primitive organisms can be controlled in the same way. One possibility is to dry up the area or at least allow the area to dry out between irrigations. Another possibility is to fertilize the affected area. Cover the area with one half to three quarters inch of composted manure. This increase in fertility will discourage moss and algae growth. A third possibility is to reduce the shade and increase air circulation. Finally, spray the area with a copper fungicide. Copper compounds are toxic to mosses, alga and slime molds. A periodic spray of the area should eliminate the problem. Use all copper materials according to container label instructions.