Does the prohibiting of Kilayim apply to hydroponics

Question

According to Halacha, does the prohibition against Kilayim, mixing different types of vegetables/grafting different types of trees together apply if they are grown on hydroponics, or no? Would it be different for vegetables vs trees?

Answer 1

Rambam Klayim 5:16 says that it is rabbinically prohibited:

וְכֵן הַזּוֹרֵעַ בְּעָצִיץ שֶׁאֵינוֹ נָקוּב הַמֻּנָּח בַּכֶּרֶם לֹא קִדֵּשׁ וּמַכִּין אוֹתוֹ מַכַּת מַרְדּוּת. אֲבָל עָצִיץ נָקוּב הֲרֵי הוּא כְּאֶרֶץ

Similarly, if one sows these species in a flowerpot that does not have a hole which is located in a vineyard, the produce is not hallowed. He, however, should be given stripes for rebellious conduct. If, however, the flowerpot has a hole, it is [as if he sowed] in the ground

Although, it may sound like this is only referring to a case of a plant that is in a vineyard, but not a case of planting two varieties in the same plug (from my experience, there’s only one seed per plug in hydroponics, but you never know), the source of the Rambam is a Gemara in Menachos 70A which is very clear:

אמר רב טביומי בר קיסנא אמר שמואל הזורע כלאים בעציץ שאינו נקוב אסור

Rav Tavyumei bar Kisna says that Shmuel says: With regard to one who plants diverse kinds of plants in a non-perforated flowerpot, this is prohibited.