In Israel there is a proverb that says, "we can learn from trees!"
Each year most of Israel's rainfall falls between the onset of winter and Tu B'Shvat (15th of Shvat) - which usually falls between mid January to early February each year.
Just as trees need water and sustenance inorder to survive, grow and thrive, man needs spiritual sustenance in order to survive, grow and thrive.
Tu B'Shvat is the time when the first trees of the field - usually the Wild Almond called the "Bride of the Field" - start to blossom.
And... just as trees bear fruit in their season, man also bears fruit in his season.