There are times throughout the year where it is an especially powerful time to daven, or there is a time in someone’s life where they need a special prayer said.
For those of you who may not have made the Birchas Ha-Ilan, the blessing on first seeing blossoming trees, it is best to recite this Brocha in the month of Nissan, which will be ending Wednesday evening--tomorrow(!)--at sunset.
You can find the bracha in almost any siddur.