"Tu" (the Hebrew abbreviation of 15th) in the month of Shvat was set (Hillel's opinion generally overrules Shammai's) as the beginning of the tithable year for tree fruit: Calculating the tithe on fruit starts again for fruit that sets after that date.
While my neighbors were putting their Christmas trees to the curb, in what seems like a ritual of replacement, I was preparing to plant for Tu BiShvat.
Tu BiShvat is a reminder that we spend our lives planting seeds. Time and effort are needed for our efforts to bear fruit. Wait patiently. One day, like the seed, we will be blessed.