Apple blossoms would be the precursor to the actual apples that could be harvested later on. The speaker cannot harvest her apples like the other women mentioned in the poem, because she plucked her blossoms before they could be fertilized and could mature into fruit.

One way to look at the apple gathering is as a metaphor for marriage and motherhood. The pink apple blossoms represent a virginal, youthful state, while the apples suggest sexual consummation or even pregnancy.

Based on this interpretation, the speaker may have put apple blossoms in her hair in preparation for her impending marriage. However, her courtship with Willie did not last. Because of this, the speaker remains unmarried and virginal while her same-aged peers are all reaping bountiful harvests—which might suggest sexual encounters and fertility. This is why the speaker can’t harvest any apples: she placed her faith all in one man to be her husband, neglecting the possibility that it would not work out. Now, she is left empty-handed.

Apple blossoms, the flowers containing the eggs that develop into fruit if fertilized, are pink. So, the superficial answer is that the flowers of an apple tree are pink, meaning that if the narrator choose to put apple blossoms in her hair she was choosing to wear pink flowers.

On a deeper level, pink is traditionally interpreted as being the color of eternal love, the color of memories of love lasting forever. The poem, on this level, is a tribute to the love once shared by the narrator and Willie, who is now dead.

Because the narrator "plucked pink blossoms from mine apple tree," she later in the year "found no apples there." The main part of the poem is spent reflecting on the loving pairs of individuals who have been able to gather apples from other trees. She is left with only her memories, which she counts of more worth than the apples gathered by the others.