PERENNIAL FLOWERS. 
159 
Perennial plants have much the advantage over 
annuals and biennials, for when they are once planted, 
they continue for several years in beauty; and many 
of them increase freely by offsets, suckers, and divis¬ 
ion of their roots. Their cultivation consists princi¬ 
pally in cutting off the flower stems, when they are 
past flowering, reducing such as extend themselves 
too freely to within a moderate space, and enriching 
the soil every year or two, with a manure compost, or 
fresh soil. 
When they remain too long in one place, they de¬ 
cline in vigor, and flower feebly; in this case they 
should be taken up, their roots divided and planted 
in fresh soil, or if restored to their former position, 
the ground should be well manured and dug deeply. 
The Perennial plants may be increased in many 
ways, but those principally adopted are by seeds, cut¬ 
tings, suckers, layers, and division of the roots. 
Seeds. —The seeds may be sown in spring, in beds 
set apart for that purpose, and when the plants are of 
sufficient size, they should be transplanted into the 
flower garden to the situation where they are to remain 
for flowering, or they may be sown in spare places in 
the beds or borders, and there remain. If too thick, 
they should be thinned when the plants are an inch or 
two high. 
Cuttings. —This method is usually practiced with 
choice herbaceous plants, that increase slowly by roots, 
as double scarlet Lychnis, double Rockets, Phloxes, 
&c., and is performed by cutting off some of the 
