PERENNIALS 89 
an uninterrupted stretch of bloom for approxi- 
mately nine months of the year; a thin showing 
at both ends, it is true, but neither quantity nor 
variety is everything in the flower garden. With 
coddling, it is possible to extend this stretch 
through December, January and February and 
thus make a complete circle of the year. 
Perennials as a class bloom only once a year. 
Most adhere to this rule with absolute rigidity; 
the exceptions usually are early spring flowers that 
a mild autumn causes to bloom sparsely a few 
months ahead of time or summer flowers that 
have a second spurt, often because the first crop 
of seed has not been allowed to mature. Nor is 
the average period of perfection of bloom long; 
sometimes it is lamentably brief and rarely is a 
perennial so prodigal as the plumy bleeding heart 
(Dicentra formosa), which has blossoms from 
spring to autumn. 
The actual time of bloom is fixed only so far 
as habitat—the place where the plant is native— 
is concerned. Even then the season, especially an 
early or late spring, will shift normality a little 
one way or the other. In gardens a similar in- 
exactitude of time, but more of it, is to be noted. 
Comparatively few perennials are cultivated in re- 
gions where they grow naturally. Not infrequent- 
ly there is a marked change of altitude; thus a 
primula native to the mountainous heights of Switz- 
erland will bloom earlier in a New York garden, 
because in the latter the snow disappears earlier. 
