66 A TEXT-BOOK OF GRASSES 
seeds are small and should not be covered deeply. It is 
important to keep the lawn as free as possible from weeds 
while becoming established. After the grasses have formed 
a firm sod or turf, weeds have little chance to intrude. 
If the soil and the applied manure be free from weed seeds, 
the task of weeding during the first season will be much 
simplified. 
85. Subsequent care.—The lawn should be frequently 
mowed, watered, weeded, and rolled if it is to be brought 
to its maximum effectiveness. If unfavorable circum- 
stances have caused the death of the grass in spots or if 
in small areas the grass failed to grow, here the weeds 
appear later. Such spots should be reseeded. It is much 
easier to obtain a uniform stand at the first sowing than 
to patch up afterward an irregular stand. Some weedy 
grasses make a good appearance early in the season but 
later die out, leaving unsightly bare patches in the sum- 
mer. This is true of crab-grass and annual blue-grass 
(Poa annua). 
86. Watering.—Blue-grass lawns usually require for 
their best development more water than is supplied by the 
natural rainfall. This is especially true during the dry 
periods that usually occur during summer. Artificial 
watering by garden hose is the usual method of meeting 
the deficit. The water should be applied in the late after- 
noon or evening as damage may result from watering dur- 
ing the heat of the day. Water should not be applied in 
full force direct from the nozzle, as the soil may be washed 
away from the roots. A spray nozzle prevents this. 
Thorough soaking from time to time is better than more 
frequent light sprinkling. Light and frequent sprinkling 
encourages a shallow root-system, readily injured by 
drought. 
