1,196. Minimum Sizes of the Four Species

Hilchos Shofar, Succah v’Lulav 7:8

The lulav may not be shorter than four handbreadths (about 12”). However much longer it gets, it remains valid. The length is only measured by the spine and not from the tips of the leaves. The myrtle and the willow may not be shorter than three handbreadths (about 9”). However much longer they get, they remain valid. Even if each branch has only three fresh leaves on it, they are valid so long as the leaves are at the top of the branch. If one bound the other species with the lulav, the spine of the lulav must extend a handbreadth or more (3”+) beyond the myrtle and the willow. The smallest acceptable esrog is the size of an egg. However much larger it gets, it remains valid.

Hilchos Shofar, Succah v’Lulav 7:9

Once a person has picked up these four species, whether he picks them up together or in succession, whether he uses his right hand or his left hand, he has fulfilled his obligation so long as he held them in the direction in which they grow. If one does not hold them in the direction in which they grow, he has not fulfilled his obligation. To perform the mitzvah properly, one must pick up the three bound species in his right hand and the esrog in his left hand. He then waves them back and forth, up and down, shaking the lulav three times in each direction.