PERENNIAL BORDERS 103 
If you are not entirely successful in keeping the 
ground covered with perennials, plant annuals to fill 
the vacant places; they may also be used while the 
perennials are too small to fill their allotted spaces. 
Keep the ground 
covered; if you do not 
succeed, nature will do 
it for you. In fact, the 
best way to learn how 
to make a border is 
to observe how nature 
does it along any coun- 
try roadside. 
Begin planting as 
soon as the frost is out 
of the ground in the 
spring, and continue 
during the whole sea- 
son, until the ground 
is frozen in the fall. 
Fic. 51. A Perennial Border 
Culture. Remove all Botanic Garden, Harvard University 
weeds from the border 
while they are young; pulling large weeds will loosen 
bulbs and roots. Keep a loose layer of soil on the surface 
to retain the moisture; lawn clippings or coarse manure 
will sometimes answer the purpose. When manure is 
used it must be free from weed seeds. In the fall, after 
the ground.has frozen, rake off all the tops that have 
died down and cover the border with a heavy layer of 
