

looking, whereas with Snowmold it is 
possible to pick out distinct patches even 
though there may be so many of these 
that they merge into large areas. Further- 
more, the appearance of grass after an 
attack of Snowmold is a distinct bleached- 
out pallor, totally unlike anything else. 
Grass damaged by being walked on 
when it is frozen and not protected by 
snow has somewhat the appearance of 
Snowmold injury. However, it is usually 
possible to distinguish the pattern of foot- 
print damage. Any traffic over grass in 
winter should be avoided if possible. 
Snowmold does not always destroy what 
it attacks. Sometimes only the topgrowth 
is affected, other times the roots are killed 
and recovery is impossible. 
Most reports of severe Snowmold dam- 
age come from the more northerly lati- 
tudes, particularly from Boston west to 
Cleveland, Chicago, and up to Minneapo- 
lis. In some years there is considerable 
damage much farther south, as far as Vir- 
ginia and Kentucky. Such was the case 
in the winter of 1942-43 when damage 
was pretty general from those states north. 
Injury of Snowmold is most apt to show 
up after a thaw in the late winter. As 
snow is melting a good condition for the 
disease is present since under the snow 
there will be a surplus of water and a 
temperature slightly above freezing. 
Checking the Disease 
As far as the average lawn is concerned, 
the likelihood of severe damage is so 
remote as to preclude any necessity of 
worrying about it. However, where past 
experience has shown that there is a con- 
dition favorable for Snowmold, it may be 
wise to take preventive measures. 
Certain mercurial fungicides such as 
used on putting greens for the control of 
Brown Patch, have been found effective 
against the Snowmold fungus. A good 
combination is one ounce of Corrosive 
Sublimate with two ounces Calomel 
applied to 1000 square feet. However, 
these materials are difficult to obtain in 
war times. So are the usual commercial 
mercury preparations such as Calo-Clor, 
2 

As snow recedes from the slope, Snowmold 
damage becomes apparent. It gets progressively 
worse toward lower level because of greater 
excess moisture. 
Semesan and Nu-Green. In the search for 
substitutes the Bayer Semesan Company 
has produced a new fungicide known as 
Thiosan. This has been found effective 
as a preventive in controlling Snowmold 
as well as Brown Patch when used at the 
rate recommended by the manufacturers— 
about three ounces to the 1000 square feet. 
If a lawn area is to be treated, the fun- 
gicide should be applied in late fall or 
early winter, preferably before any heavy 
snows. One treatment should suffice. It 
should be put on with a pressure sprayer 
or sprinkling can, or mixed with dry sand 
or soil and spread by hand. Those not 
having spraying equipment can get Scotts 
Turf Fungicide, mixed with a dry carrier 
for easy hand application. 
It is not necessary to treat the whole of 
a large lawn, but only those sections where 
conditions are favorable for Snowmold, as 
for example, the bottom of a slope where 
there is apt to be a surplus of water result- 
ing from snow melting on higher ground. 
The same may be true of areas where 
large piles of snow and ice are thrown 
up in cleaning walks and drives. These 
should be avoided if possible. If grass 
is covered with manure, straw or other 
mulch materials, it is more apt to suffer 
