This is a hint that we musn't diminish the value of any Jew by looking at what he lacks. Therefore we bind all the species together on the Lulav as the central figure. The Lulav which must be straight and tall, represents a Tzaddik to whom every Jew needs to connect himself. The Tzaddik is that person who is one's spiritual teacher, who shows him the way and helps him to do the soul work which is his to do in the world. Only when all the species, i.e. Jews, are bound to their teachers, then there is the possibility of blessing.
Unity is a prerequisite for the bestowal of blessing.
May we all be fortunate to find spiritual teachers who will be able to guide us in the path of Torah and Mitzvahs , and teach us to serve Hashem with pure joy. LOVE It is brought down that the month of Elul , Rosh HaShanah and Yom Kippur are designated for doing Teshuva. A Jew is inspired and cajoled into teshuva as he comtemplates the awesomeness of the Creator and how we are obligated to Him. It is a teshuva based on fear and awe. When Sukkos , the season of our rejoicing comes, the process of teshuva takes a new course.