http://revach.net/article.php?id=1081

Section: Halacha   Category: Tshuvos
7 Things To Look For When Buying A Lulav
  1. Closed - The primary issue is to insure that the middle leaf is completely closed all the way to its tip.  Preferably, one should not even be able to see two separate points. 
  2. Not Dry - Also, it is important that the lulav has not dried out and shriveled, but a little brown on the tip is natural. 
  3. Complete  - Furthermore, care must be taken that the tip has not broken off.   
  4. Covered In Brown - Some prefer to take a lulav where the tip is covered with brown korah insuring its complete closure, while others avoid such a lulav out of concern for what lies underneath. 
  5. Knepel - Also, some prefer a knepel, where the tip of the leaf is folded over, as such a lulav will almost never split.  However, some poskim invalidate such a lulav because of its bent state. 
  6. Shape - A lulav that bends slightly but not so much that the tip points back to the bottom of the lulav is not a problem and has all the advantages. 
  7. Beauty - A long, thick, straight and green lulav is ideal, but not of primary importance.

    Feel free to ask any questions you may have for Rabbi Moncharsh at www.revach.net/ask

    Important Note:  It is important and customary that once you have your Arba Minim to show them to your Rav to make sure they are kosher.