"For the Lord your God is bringing you into a good land, a land with streams and springs and fountains issuing from plain and hill; a land of wheat, barley, of vines, figs and pomegranates; a land of olive trees and (date) honey." (Deut. 8:7-8)
The seven species are the fruits that the land of Israel is blessed with. This brings plenty, health and prosperity to your home.
 
Wheat - the symbol of wisdom and knowledge.
Barley - the symbol of material.
Grape Wine - symbolizes joy.
Fig - the symbol of the Torah.
Pomegranate - symbolizes abundance, fertility and beauty.
Olive - the symbol of happy family life.
Date / Honey - the symbol of good and sweet life.