Tu Bishvat is the Rosh Hashana for trees.
As man is called a tree, therefore on Tu Bishvat there is a lesson.
It states, that the world was given in the heart.
The meaning is, that in addition to the fact that the world was created for the Jewish people, every aspect of the outer world is within each heart – and in fact, the outer reality is only from the inner.
More specifically, it is known, that the Jewish people are called a choice land.
Land in Hebrew also means run – for they run to do the will of G-d.
Land in Hebrew also means desire – that they desire to do G-d’s will.
From this we understand that within every Jew are all aspects of what is within land.
And in particular the seven types of fruit/produce that Israel was blessed with – “a land of wheat, barley, grapes, figs, pomegranates, a land of Olive oil, and honey” (from dates.)
In fact the Jewish people are called by these names: “God’s first produce” and also “all types of beautiful and beneficial fruit trees.”
As Tu Bishvat is the new year for trees hence the aspect of land and trees within the Jews are renewed.
The difference between trees and produce (grains) is the former (it’s fruit) are there to add in the pleasure of man, while the latter is necessary for life.
In addition, both quantitatively and qualitatively, the seeds of the fruits produce not only an abundance (for a wheat kernel produces only a few more) as well as a product, which is Infinitely greater.
This is analogous to when we serve God with joy, that we abundantly add.
And this addition is not only quantitatively, but also qualitatively.
On Tu Bishvat we get a revived energy, relating to being joyous, which effects all other aspects.
Our sages teach, that the reason God sent the Jews into exile, is as He wishes to promote his name – hence as the Jews dedicate their lives to Him, they serve as role models.
The planting of the Jew begins with his soul coming into this world.
Specifically the way the Jew reveals God is through doing the Mitzvos.
Hence the Jewish people who have been given these Mitzvos have a great duty.
Simalerly, within every every Jew there is both the Divine soul and animal – why did the Divine soul descend into the animal (spirit), because precisely the inspired animal cuases the greatest yield.
However to spark the ground’s yield, as in placing the seed that cuases the ground’s growth to manifest, we first begin with the inspiration of the Divine soul, which acts as a catalyst for the animal (spirit) which then through it’s tremendous yield elevates the Godly.
Now after we have begun our purpose, we get to higher levels:
Firstly grapes, which represent the essence, for through squeezing them the inside comes out – simalerly, we must manifest our Divine essence.
We have completed the work in exile, hence are completely ready for redemption!