Translation from CQ44:
The plum tree bent under the winter freeze,
With showers, all at once opens its buds.
The moon, through mists, projects its shadow
In the dark, breezes carry its scent.
A few days back, the trunk was buried in snow,
Now, branches bear flowers anew.
Through hardship and the bitter cold -
This dignity, at the forefront of spring.
Different translation from terebess:
In past years, winter cold has afflicted the plum;
Getting rain for once, it blooms!
Scattered shadows—as the moon shifts they move the other way;
A dark fragrance—the breeze comes with it.
The tree that was buried in snow yesterday—
Its branches again bear flowers now.
Suffering the distress of winter cold—how much?
How precious—this paragon of all the plant kingdom.
By Zen priest Hakuin (1685-1768) in his commentary on the Heart Sutra.
I guess the plum blossoms spring forth with the first spring rains.
Soshitsu XV contrasts the plum blossoms with the exuberance of the cherry blossoms, and finds the plum blossoms more refined, elegant, noble; the restraint of the scent and the blossoms thus give a sense of profoundness.
It is seen as a symbol of struggling and enduring through the winter (of our lives), and bring forth after this hardship something dignified.