Silvery Thread Moss

Weeds

moss, silver moss

Bryum argenteum

Photos

Moss appears as tufts or patches of finely textured plants and is usually associated with excess surface moisture as a result of frequent irrigation cycles, heavy shade, or poor surface drainage. Silvery thread moss is the most common species found in turfgrass, usually appearing on putting greens and in shaded back yards. Moss is commonly observed in the dominant gametophyte generation which is comprised of tightly packed individual male and female plants. Fertilization of the female plants is facilitated by moving water or traffic. The sporophyte generation grows parasitically on top of the mother plants. When mature, the fruiting body explodes, disseminating the spores for future generations. Asexual reproduction occurs by breaking away small fragments of moss; this process is called fragmentation. This vegetative spread is probably very common in turf via foot traffic and mowing.

Crops Affected: turf

Management

Moss is an indicator of excess surface moisture, usually as a result of frequent irrigation or long irrigation cycles. Poor drainage and heavy shade can also contribute to conditions conducive for moss growth. Reducing surface moisture is critical to diminishing the occurrence of moss long term. The desiccating tissue may need to be removed to allow regrowth of the turf. Improving air movement and increasing exposure to morning sunlight can also disfavor the moss and improve the growing conditions for the turf. Lightweight greens rolling (3X per week) has been shown to reduce moss populations on putting greens from year to year. Correcting cultural conditions is much more effective at preventing the establishment of moss than at removing existing patches.

Similar Species

There are no 'higher' plants confused with moss. However, at putting green height moss can appear grass-like, but usually exhibits a darker-green color and bumpy appearance.

MSU Extension Turf