Monday, April 15, 2013

Snow Mold

This snow mold seems to be actually growing from the snow. Or perhaps, as is more likely, the mycelium was growing in the melt water between the ice crystals and as the snow melted away it draped the web of mycelium fibers on top of the grass. In the spring time great mats of the stuff are revealed on the grass as the snow melts away. The threads are even more delicate than a spider's web and only remain visible for a day or two after the snow melts away.

Snow mold is a fungus that feeds on grass in cold wet weather. It doesn't necessarily need snow and is a problem for golf courses and other turf grower even where it does not normally snow. There are several different types of snow mold; the two most common being the grey snow mold and the pink snow mold. I believe the above image is of the grey snow mold as the reddish-brown sclerotia are visible embedded in the grass leaves. In the image below you can more clearly see one of the sclerotia after the thatch has dried a bit and the mycelium has disappeared. The sclerotia is the dormant form of the fungus that stays in the thatch through the hot and dry weather of the summer. The fungus starts growing again in the fall when the necessary cool and wet conditions are present.

The pinkish hue on the lower portion of the grass leaf in the above picture is a bit of a mystery. There are patches of this faint pink on the dead thatch all over the grass. I thought it might be from the spores of pink snow mold but I am no longer sure. I couldn't find any good close-ups of what pink snow mold is supposed to look like. All the pictures I found on the web were only useful for identifying the circular patches of dead grass it creates in lawns and golf courses.

No comments:

Post a Comment