"Coming" is a symbolic, powerful poem about time, aging, and the passing of seasons. Typically, the transition from winter to spring is depicted as a positive and optimistic time, an advancement from the lifelessness of winter to the vitality of spring. However, in this poem Larkin subverts this idea, suggesting that spring is actually a time of false hope.
Part of the reason why spring is a time of false hope is that it suggests life is a cycle that continually moves from death to rebirth. As such, people often have a positive view of the spring because it signals hope for a new beginning. Positive feelings are attached to this, making Spring a happy season for many people.
However, in this poem, Larkin suggests that spring does not represent new beginnings and that there is a false optimism associated with the season. Instead, the coming of spring also represents the inevitable passing of time, and therefore the looming presence of death.