Kilayim - GrowTorah Q&A

Kilayim is a prohibition against combining certain plants and animals. In this section questions of planting and kilayim are raised, such as if this prohibition applies to vegetables, if it applies to fruits, and if one can eat products of cross-pollination.

 
 
 

1. Does kilayim apply to vegetable planting?

Kilayim does apply to vegetable planting, but only in the land of Israel.

There are 5 different kinds of kilayim (כלאים): forbidden mixtures

  1. Shatnez (שעטנז) applies only in clothing, inside and out of Israel.

  2. Harkavat Behemah (הרכבת הבהמה): cross breeding of animals applies inside and out of Israel

3 kinds of kilayim apply to produce:

  1. Kila’ei HaKerem (כלה הכרם) involves a grape seed. In order to avoid the Torah prohibition, the Jewish people accepted a major leniency. For it to be considered kila’ei hakerem, the kilayim need to be inside the kerem (כרם): vineyard. In addition to the grape seed, there must be two other vegetable/grain seeds in kilayim (כלאים) with each other in a single mixture. The Gemara explains that it needs to be a barley seed, a wheat seed, and a grape seed all within a very small area. Anything short of that would be considered a Rabbinic prohibition.

This type of kilayim is the most stringent type- one cannot plant it, and anything that grows from it is prohibited in hanaa (הנאה): enjoyment. Because of the severity, the rabbis established that the prohibition in chutz la’aretz (חוץ לארץ): outside the land of Israel, is purely rabbinic. The Rama rules in Yoreh De’ah (296:69) that the only prohibition in chutz la’aretz would be planting/eating things that would have a Torah prohibition inside of Israel. One would have to work very hard in order to reach this problem outside of Israel. Overall it is a Torah prohibition inside Israel but not outside. 

  1. Kilo Zeraim (כלה זרעים) occurs when two different vegetables/grains mix with each other. This kind of mixture cannot be planted in Israel, anad needs to be ripped out of the ground. People can eat the produce that grew from the mixture. 

Outside of Israel, this kind of mixture is completely allowed. Most questions of kilayim fall under this category, so there would be no issue of kilayim in the GrowTorah gardens. 

  1. Kilayim of fruit trees applies only to grafting branches. Someone is allowed to take any fruit seeds that they want and plant them together without it being an issue of kilayim. Grafting the branches is a Torah prohibition inside and out of Israel.

It is allowed to eat the fruit that comes from a grafted seed. Once the new grafted fruit produces a seed (of a new species), there is no problem planting that seed because there is no act of kilayim (mixing/grafting) involved. 

The Mishnah of Massechet Kilayim (מסכת כלאים) lists the things that are and are not kilayim ze b’ze (כלאים זה בזה): kilayim with one another. It is not an exhaustive list as it is mostly limited to the fruits that grew in the time of the Mishnah. 

Defining kilayim is a tricky since Chazal define species slightly different than modern science. Halachic decisions are not based on scientific species since they did not think in terms of genetics. Halacha is based more on appearances, so all apples are considered the same species and there is no problem to graft two different kinds of apples together.

רמ״א (רצב:סט)

כל השיעורים האלו שמרחיקין בין הגפנים והתבואה או הירק אינם אלא בא"י או בסוריא אבל בחו"ל מותר לזרוע בצד הגפנים בתוך הכרם לכתחלה ולא אסרו בח"ל אלא לזרוע ב' מיני ירק או תבואה עם החרצן במפולת יד ואם אמר לתינוק עובד כוכבים לזרוע לו בח"ל מותר אבל לא יאמר לעובד כוכבים גדול שלא יתחלף בישראל ואע"פ שמותר לזרוע הירק בצד הכרם בח"ל הרי אותו הירק הזרוע שם אסור באכילה ואפי' בח"ל והוא שיראה אותו לוקט ומוכר אבל ספיקו מותר: הגה וי"א דהואיל ומותר לזרוע ירק בצד הגפנים בח"ל מותר לאכול אותו ירק גם כן (הגהות מיימוני פ"י מהלכות מ"א דין ט' ותה"ד סימן קצ"ד) ואין לחוש אלא במקום דאיכא למיחש שנזרע ב' מיני ירק או ב' מיני תבואה עם חרצן במפולת יד (מרדכי פרק קמא דקדושין) ועל כן נהגו להקל במדינות אלו בירקות הנמצאים זרועות בכרמים כי לא שכיח שנזרעו באיסור

 

משנה כלאים א׳: א׳-ו׳

הַחִטִּים וְהַזּוּנִין אֵינָן כִּלְאַיִם זֶה בָזֶה. הַשְּׂעֹרִים וְשִׁבֹּלֶת שׁוּעָל, הַכֻּסְּמִין וְהַשִּׁיפוֹן, הַפּוֹל וְהַסַּפִּיר, הַפֻּרְקְדָן וְהַטֹּפֵחַ, וּפוֹל הַלָּבָן וְהַשְּׁעוּעִים, אֵינָם כִּלְאַיִם זֶה בָזֶה

הַקִּשּׁוּת וְהַמְּלָפְפוֹן, אֵינָם כִּלְאַיִם זֶה בָזֶה. רַבִּי יְהוּדָה אוֹמֵר, כִּלְאָיִם. חֲזֶרֶת וַחֲזֶרֶת גַּלִּים, עֻלְשִׁין וְעֻלְשֵׁי שָׂדֶה, כְּרֵשִׁים וּכְרֵשֵׁי שָׂדֶה, כֻּסְבָּר וְכֻסְבַּר שָׂדֶה, חַרְדָּל וְחַרְדָּל מִצְרִי, וּדְלַעַת הַמִּצְרִי וְהָרְמוּצָה, וּפוֹל מִצְרִי וְהֶחָרוּב, אֵינָם כִּלְאַיִם זֶה בָזֶה

הַלֶּפֶת וְהַנָּפוּץ, וְהַכְּרוּב וְהַתְּרוֹבְתוֹר, הַתְּרָדִים וְהַלְּעוּנִים, אֵינָם כִּלְאַיִם זֶה בָזֶה. הוֹסִיף רַבִּי עֲקִיבָא, הַשּׁוּם וְהַשּׁוּמָנִית, הַבָּצָל וְהַבְּצַלְצוּל, וְהַתֻּרְמוֹס וְהַפְּלַסְלוֹס, אֵינָן כִּלְאַיִם זֶה בָזֶה

וּבָאִילָן, הָאֲגָסִים וְהַקְּרֻסְתּוּמֵלִין, וְהַפְּרִישִׁים וְהָעֻזְרָדִים, אֵינָם כִּלְאַיִם זֶה בָזֶה. הַתַּפּוּחַ וְהַחַזְרָד, הַפַּרְסְקִים וְהַשְּׁקֵדִין, וְהַשִּׁזָּפִין וְהָרִימִין, אַף עַל פִּי שֶׁדּוֹמִין זֶה לָזֶה, כִּלְאַיִם זֶה בָזֶה 

הַצְּנוֹן וְהַנָּפוּץ, הַחַרְדָּל וְהַלַּפְסָן, וּדְלַעַת יְוָנִית עִם הַמִּצְרִית וְהָרְמוּצָה, אַף עַל פִּי שֶׁדּוֹמִין זֶה לָזֶה, כִּלְאַיִם זֶה בָזֶה

הַזְּאֵב וְהַכֶּלֶב, כֶּלֶב הַכֻּפְרִי וְהַשּׁוּעָל, הָעִזִּים וְהַצְּבָאִים, הַיְּעֵלִים וְהָרְחֵלִים, הַסּוּס וְהַפֶּרֶד, הַפֶּרֶד וְהַחֲמוֹר, הַחֲמוֹר וְהֶעָרוֹד, אַף עַל פִּי שֶׁדּוֹמִין זֶה לָזֶה, כִּלְאַיִם זֶה בָזֶה 




Mishnah kilayim 1:1-6

Wheat and zunin do not constitute kilayim one with the other. Barley and oats, spelt and rye, or beans and sapir (a type of bean), or purkdan and tofah (two similar types of beans), or white beans and kidney beans, do not constitute kilayim one with the other.

Cucumbers and melons do not constitute kilayim one with the other. Rabbi Judah said they do constitute kilayim. Lettuce and wild lettuce, endives and wild endives, leek and wild leek, coriander and wild coriander, or mustard and Egyptian mustard, Egyptian gourd and the bitter gourd, or Egyptian beans and carob shaped beans do not constitute kilayim one with the other.

Turnips and the cabbage turnip, cabbage and cauliflower, beet and rumex do not constitute kilayim one with the other. Rabbi Akiva added: garlic and small wild garlic, onion and small wild onion, lupine and wild lupine do not constitute kilayim one with the other.

As for trees: the pear and the crustumenian pear, the medlar and azarolus, do not constitute kilayim one with the other. The apple and the crab-apple, or the peach and almond, or the jujube and rimin, even though they are similar one to the other, they nevertheless constitute kilayim one with the other.

The radish and the cabbage turnip, mustard and charlock mustard, Greek gourd with Egyptian gourd or [Greek gourd] with bitter gourd, even though they are similar one to the other, are nevertheless kilayim one with the other.

A wolf and a dog, a wild dog and a fox, a goat and a deer, a gazelle and a ewe-lamb, a horse and a mule, or a mule and a donkey, a donkey and a wild donkey, even though they are similar one to the other, constitute nevertheless, kilayim one with the other.

 

2. Does kilayim apply to fruits?

Kilayim does apply to fruits, but in order for the mix to be considered kilayim, someone would need to graft the branches of two different species together. This would be a Torah violation inside and outside of Israel. 

It is unclear whether the prohibition against grafting applies to non-fruit bearing trees. If the main concern is the grafting itself, then the product doesn’t matter. If the problem is with creating new fruits, then a lot of grafting would not be a problem since not all grafting makes new fruit. It is possible that all of the species mentioned in the Mishnah are in similar families of species so one could technically graft (i.e. it would work botanically) but it would be prohibited as kilayim. 

 

3. Can one intentionally cross-pollinate or eat food that has been cross-pollinated? 

The question refers to two different species (i.e. melon and squash) that can, in many situations, pollinate each other and produce some kind of hybrid. 

In chutz la’aretz (חוץ לארץ), one can plant them together and whatever happens is fine. Even though hand pollination is done in an intentionally crafted manner, there seems to be no reason why it would be prohibited. Kilo zeraim (כלה זרעים) is not a problem in chutz la’aretz. It is also not a problem if there are no fruit trees involved, since they are the only case where grafting would be prohibited. Even for fruit trees, there does not seem to be a clear prohibition and for vegetables it is not even clear what the prohibition would be.

 

4. How does kilayim apply to raised beds? I have wheat growing in two beds and I’d like to grow grapes in a nearby bed, growing along a fence that borders the wheat, do I need a tzurat haPetach (צורת הפתח)? 

According to the Rama, it is not an issue outside of Israel since it would be considered kilo hakerem (כלאי הכרם) which is specifically for wheat and grapevines. 

Generally, if there are two things next to each other that are kilayim, putting a wall between does away with the problem (E.g. grapes on one side, wheat on the other). If the grapevines were part of a vineyard, then there would need to be 8 or 16 amot (אמות- cubits) separation between them. But if there is a wall, then one does not need to worry about separation, and the produce on either side can go up to the wall and it would not be an issue. 

Tzurat hapetach (צורת הפתח): a door frame made of two poles and a crossbar, can function as a wall. It is a bit difficult practically because one would need to ensure that the foliage does not cross over the frame into the other type of produce. If it is successful, then that would help the produce avoid the problem of kilayim. It would be difficult to come across kilo hakerem (כלה הכרם) questions outside of Israel, but not impossible. 

In Israel, a raised bed would have to qualify as a mechitza (מחיצה- separation) in order to avoid the problem. This means that the raised beds would need to be tall enough, at least 10 tfachim (טפחים- handbreadths) which would constitute a wall, assuming that the foliage is not hanging over the separation. Raised beds should be constructed in such a way that the mechitza would function as a wall. 

 

5. Are GMOs kilayim? What about hybrid crops, breeding, etc?

We assume that GMOs (genetically modified organisms) are not kilayim. If there was a prohibition of splicing genes in certain contexts, once someone has the new seed, it is now considered its own species so there would be no problem planting and eating it. 







HalachaYosef GillersKilayim, Halacha