I have heard of potatoes, celery, scallion. What else do people use for Karpas? Is there one item that is more L'Chatchila than the others?
Other green haadama options are pepper, honeydew, tomatillo, artichoke, okra, asparagus, broccoli, zucchini, cucumber (and if you get pickles they are effectively pre-dipped).– Double AA ♦Apr 10, 2022 at 2:48
Another one popularly used is onion. Per this answer to a previous question, there are also people who use bananas.
Also heard of radishes and carrots
I can't believe nobody has mentioned the controversy with parsley yet. Many, many people use parsley, but several Aharonim/Poskim have criticized this, because they hold that Karpas should have a Berachah of Borei Peri HaAdamah, whereas parsley may only warrant a SheHaKol as an herb. http://www.raananakollel.org/articles_pesach_halachot_of_pesach.html
For this reason, my father uses parsley (as, supposedly, the literal meaning of karpas) with some cooked potato.– msh210 ♦Mar 23, 2011 at 22:28
Seth, you have a good point, but in the same vein I cannot believe you did not bring up the controversy regarding raw onion which would be a Shehakol for the same reason as parsley - Not merely because it is an herb, rather because it is not normally eaten raw on its own as a main food. All that being said, there are many customs of the seder night which can be called into question from a halachic perspective and a sefer specifically dealing with these issues is in my opinion a desideratum non artificiosus in the corpus of new Halachic literature that has exploded over the last century.– YahuMar 24, 2011 at 8:30
Yahu, I didn't mention the controversy with onion, frankly, because I'd never heard of eating onion as Karpas. Parsley is widely used, for linguistic reasons as well as neo-traditional reasons (I grew up with my parents doing it, so I'm going to do it, although I have no idea why or whether or not it's correct), but its use has been called into question due to the problem with its Berachah. Now, why one needs to say HaAdamah on Karpas is another question altogether.– Seth JMar 24, 2011 at 16:50
Most understand it to mean parsley or celery but others hold it derives from any harvest food of the ground. The truth is that the halachic sources speak about the same issues regarding the alleged Greek or Persian roots of the word or the common root of both of them.