166 ALPINE PLANTS 
after they have flowered profusely for one or perhaps 
two seasons. A word of explanation may serve to show 
how these collapses may be avoided. 
The Phloxes are among those plants that grow on their 
native mountains in broad masses where avalanche and 
torrent sweeping down the mountain side during spring 
thaws carry down grit, decaying vegetation, and frag- 
ments of rock that smother the plants with what we are 
accustomed to call a natural mulching. The Phloxes 
have become so accustomed to this rough-and-ready care 
of nature that they thrust forward their leafy growths 
on the extremities of long bare stems. Then when these 
stems are buried in the gritty mixture that is washed down 
upon them, they throw out innumerable roots, and the plants 
renew growth with greater vigour and over a still greater 
area. In our gardens the mulching of the plants is too often 
neglected. The long, bare stems are produced, but they 
are left exposed to drying wind, frost, and sun, with the 
consequence that they become hardened and shrivelled 
to such an extent that they become incapable of con- 
veying sap from the roots to the starving growths at their 
extremities. A season’s flowering under these conditions 
so completely exhausts these growths that they collapse, 
and the whole plant dies off. A common practice is to 
cut back the old growths, inducing the plants to break 
up afresh from the base. They will do this, but to 
compel them to do so season after season is to weaken 
the growth and exhaust the root system. A far better 
plan is to trim out the smaller weak growths after flowering, 
peg down the long rambling stems with hairpins and 
