Summer is fading:
The leaves fall in ones and twos
From trees bordering
The new recreation ground.
In the hollows of afternoons
The idea of leaves falling in “ones and twos” suggests the obvious loss of vigorous life experienced by the young mothers referred to later. That it is summer compounds the tragedy; this should be a time of energy and happiness. 
 Note that this line is a  monosyllablic string , with elongated vowels. The effect is to slow the pace and suggest tedium.
Afternoons