Overnight, very
Whitely, discreetly,
Very quietly
Our toes, our noses
Take hold on the loam,
Acquire the air.
Nobody sees us,
Stops us, betrays us;
The small grains make room.
Soft fists insist on
Heaving the needles,
The leafy bedding,
The soil makes way: Plath subtly characterizes the soil as being a passive enabler of the mushrooms' growth: its grains simply “make room” rather than, for example, “get pushed out of the way”. 
 
 The four monosyllabic words, and the full stop which completes the line, suggest inevitability. The emphatic monosyllables with elongated vowels sound ponderous if read aloud, giving the line emphasis.
Mushrooms