Tu B'Shevat, the new year of the trees, is often celebrated with the 7 species for which the Torah praises the land of Israel: “A land of wheat and barley, of vines, figs and pomegranates, a land of olive oil and honey (from dates)” (Deuteronomy 8:8).
Wheat (chitah): The Sages noted the importance of wheat in Pirkei Avot (Ethics of the Fathers 3:21): “Where there is no flour, there is no Torah. Where there is no Torah, there is no flour.”
Barley (seh’o’rah): At Passover time, the omer offering (a measure of barley from the new harvest) was brought to the Temple, symbolic of the start of the spring harvest.
Grape (gefen - literally grape-vines): The transformation of grapes into wine reflects humankind’s ability to choose to uplift itself or debase itself depending upon how they use the grape.
Fig (t’aynah): “... All the figs on one tree do not ripen at once, rather a few each day. Therefore, the longer one searches in the tree, the more figs one finds. So too with Torah: The more one studies, the more knowledge and wisdom one finds" (Eruvin 54a).
Pomegranate (rimon): According to the Midrash, the pomegranate has 613 seeds equivalent to the number of commandments in the Torah.
Olive (zayit): “...Just as the leaves of an olive tree do not fall off either in summer or winter, so too, the Jewish people shall not be cast off--neither in this world, or in the World to Come” (Menachot 53b).
Date (tamar): While the Torah uses the word d’vash, honey, it is understood as referring to date-honey because the date is frequently boiled to make a type of honey. “The righteous shall flourish like a date-palm tree” (Psalms 92:13), for those who act holy are sweet in God’s eyes.
See also: Jewish Treats: Tu B’Shevat is Coming and Jewish Treats: Terrific Trees