Now, there isn't much you can do with the other Succot mitzvah, Arbaat Haminim, the Four Species.
"And you shall take for you on the first day, the fruit of the tree ‘hadar’ and branches of palm trees, and a bough of the tree avot and willows of the brook, and you shall rejoice before the Hashem, your G-d, seven days." Leviticus Chapter 23
The "Etrog," the Citron, resembles in its shape, the heart, the driving force behind all our actions. The "Lulav," the Palm Branch, resembles the spine, which holds the body together and, without which, we would be unable to move. The "Hadasim," the Myrtle Branches, resemble, in their almond-shape, the eyes, with which we behold G-d's World. And the "Aravot," the Willow Branches, resemble the lips, with which we give expression to our thoughts and feelings.
By holding these four together, we show that a person should devote all of his-or- her strengths and capacities to the Service of Hashem. (complete article)
The four species all taken together make up one single mitzvah. If any of the species are missing then you have not fulfilled the mitzvah at all. One lulav, one etrog, two aravot, and three hadasim is taken on Sukkot. The lulav, hadasim and aravot are bound together.
For this mitzvah we need the real thing. We can't use similar fruit or leaves. Jews have somehow managed to keep this mizvah for thousands of years, all over the world. Think about it. I find it amazing.
No other People, no other religion has kept to the same religious laws for as long as the Jewish People. And no other People have kept to their religion even after an exile as drastic and world encompassing as the Jewish Exile. And no other People has remained as loyal to its Land, even when for two thousand years the majority of the Jewish People have lived in exile. Demographers believe that we're at the point when more than half the Jewish People are living here in the Holy Land. This is a great miracle.
It's because Jews have done everything possible to carry on Jewish Life according to Jewish Law no matter how difficult.