The time of year when men begin to grow a mustache or trim their winter beard down to a mustache. The growing usually begins in March coinciding with the beginning of spring.
Mustache growing season is the conclusion of beard growing season, which starts in No-Shave November[1] and serves to keep men's faces warm during the winter. As spring time arrives, the beards are shaved off, and the mustaches come out as a sort of celebratory triumph.
Mustache growing season is the time when men grow their "staches" out for the "Stache for Cash" fundraiser being hosted by Lespwa Worldwide [1] in April to raise money and awareness for orphans and restavecs in Haiti