Symptoms
 The normal thinning which takes place during the winter
often passes unnoticed, and such fractional winter damage may
be confused with the slow growth rate associated with cool or
dry spring weather. Severely winterkilled pangolagrass sod,
having 75% or higher mortality, fails to make a spurt of growth
when moisture and temperature conditions become favorable.
Instead, it remains the uniform gray-brown color characteristic
of dead and weathered pangolagrass forage. Winter injury ap-
proaching the 100% level can be identified by a weakening of
the grass crown that permits pulling it loose from the ground
by handfuls-which cannot be done on a living sod. This con-
dition does not develop until one to two months after the actual
date of damage. Surviving buds in heavily damaged areas often
are weak and slow to develop. Recognition of extensive winter-
killing may be obscured when the sod contains a mixture of
weeds or grasses that renew growth in a normal manner.

 Distribution
 Winter damage to pangolagrass often is severe in north and
central Florida, with Alachua and neighboring counties being
the northern limit of adaptation. Injury is less common to the
south, and the zone of transition from frequent winter losses
to the area having virtually no damage on sandy land passes
through Hillsborough, Hardee and Osceola Counties (Figure 6).
 The map shows the number of times the temperature fell
to 280F or lower from November 1937 to March 1957. It can
be seen that temperatures of 28'F or lower occurred a total of
25 times during 20 seasons, as far south as Charlotte, Glades,
and Okeechobee Counties. In addition there was an area south
of Lake Okeechobee where temperatures of 280F or lower oc-
curred 25 times or more. Data from the coldest frost pockets
were not included in this summary.
 The 28'F temperature has no special significance as a critical
point in connection with winter damage to pangolagrass. Rather,
it is used as a means of showing the distribution of subfreezing
weather in the Florida peninsula and to illustrate the relation-
ship between severity of winter temperatures and pangolagrass
injury.
 Cause and Control
Cold
 Winterkilling of pangolagrass is associated with a combina-
 tion of frost and freezing temperatures. Severe damage has