For that matter, may a Jew?
I once received the following query:
“I am not Jewish, but I observe the laws of Noahides as recorded in the writings of Maimonides, which I have read in the Yale University translation. I am aware that a gentile may not graft one species of tree onto another. Does owning a nectarine tree violate this prohibition? I would be greatly appreciative if you could answer this question, since I have just purchased a house with a nectarine tree in the yard.
250 Washington Blvd.
Asheville, NC” (name and address have been changed)
Many of us reading the title of this article may have wondered, “If I am permitted to eat nectarines, why shouldn’t I own a nectarine tree?” Although the answer to this question is fairly straightforward, there are many other issues that need clarification, before we can answer Jacqueline’s shaylah.
First, let us explain the halachos of tree-grafting applicable to Jews. Sadly, because many Jews are unfamiliar with these halachos and unaware of the prevalence of grafted trees, they often, unwittingly, violate these laws.
Also, most people misunderstand the prohibition against kelayim, which is often translated as “mixed species.” People often understand this to mean a prohibition against hybridization or cross-breeding. Although it is true that the Torah prohibits crossbreeding different species of animal, virtually all other types of forbidden mixtures have nothing at all to do with hybridization. We list here the six types of prohibited mixtures, called kelayim.
1. Wearing shatnez, which is a mix of wool and linen.
2. Cross-breeding two animal species.
3. Using two animal species to haul or work together. This mitzvah is usually called lo sacharosh, do not plow with an ox and a donkey together.
4. Grafting different tree species. A sub-category of this prohibition is planting one species on top of or inside another species, a process that is virtually non-existent in contemporary agricultural practice.
5. Planting other crop species in a vineyard. For this purpose, “crop” refers to an annual (grows for only one year and then dies) edible plant. Examples are: seeds that are eaten, like beans, wheat, and sesame; root vegetables, like radish; leaves, such as lettuce; or fruit, such as tomatoes or melons.
6. Planting two crop species together or near one another. This prohibition applies only to species that are eaten.
Although we usually assume that the word kelayim means “mixture,” some commentaries explain that this word originates from the same Hebrew root as the word “prison,” beis ke’le. Thus, Rav Hirsch (Vayikra 19:19) explains that the root word כלא means to keep or hold something back, and that the plural form kelayim is similar to yadayim or raglayim and means a pair. Therefore, the word kelayim means to pair together two items that should be kept apart.
In order to explain the prohibition against grafting trees, the subject of our article, I will first provide some scientific background for city dwellers like myself, who know almost nothing about gardening and horticulture. Having been a city slicker almost my whole life, I freely admit that I knew little about this subject until I did some research in order to understand the halacha.
Hybridization (cross-breeding) of plants occurs when one pollinates the flower of one species with pollen from a different species. However, most of the prohibitions of kelayim have nothing to do with cross-breeding species. In the case of “herbaceous plants,” that is, plants other than perennial (live for many years) trees and shrubs, kelayim is a prohibition against planting two crop species close together. Halacha prohibits planting a crop species inside a vineyard, planting one species too close to another already planted species (distances vary according to how many plants are growing together), planting one species on top of or inside another species, and sowing the seeds of two species together. Incidentally, these prohibitions apply only in Eretz Yisrael, with the exception of planting a crop species in a vineyard (Kiddushin 39a) and, possibly, of planting one species inside another (see Gemara and Tosafos, Chullin 60a; Rambam, Hilchos Kelayim 1:5 and Radbaz). Thus, someone in chutz la’aretz may plant his backyard garden with a wide variety of vegetables and other edibles without any halachic concern, whereas in Eretz Yisrael, someone planting a garden patch must be very careful to keep the different species separate. The complicated question of how far apart to plant them, and what qualifies as a valid separation if one plants them close together, is beyond the scope of this article (see Chazon Ish, Hilchos Kelayim 6:1).
(By the way, the halachic definition of a species often differs from scientific definition. For example, although some scientists consider wolves and dogs to be the same species, halacha does not; therefore, one may not crossbreed them or use them to haul a load together [Mishnah, Kelayim 1:6]. On the other hand, the Chazon Ish [3:7] discusses whether all citrus fruits are the same species regarding the laws of kelayim, which would permit grafting a grapefruit branch onto a lemon rootstock, whereas scientists consider them to be two distinct species.)
HARKAVAS ILAN – CROSS-GRAFTING
The laws of kelayim also prohibit grafting a branch of one species of tree onto the root stock, or lower trunk, of another species. Although a town dweller may feel that this is a rare occurrence, in fact, contemporary plant nurseries and tree farmers usually graft branches of a species that produces delicious fruit onto the hardier stock of a different species.
For example, most modern peach and nectarine trees are produced by grafting a peach or nectarine branch onto the stock of a hardier, botanically-related tree, such as an almond. As I will explain, someone who performs this, either in Eretz Yisrael or in chutz la’aretz, violates a Torah prohibition. According to many authorities, a non-Jew is also commanded regarding this mitzvah. This latter opinion contends that a Jew who causes a non-Jew to graft such a tree, or even to prune or water it after grafting was done, contravenes lifnei iveir, causing someone else to violate a prohibition.
Because so many trees are grafted nowadays, someone who owns a peach tree should have a horticultural expert check whether its rootstock is also a peach tree, or whether it is of a different species. If the stock is peach, even of a different variety, he may keep the tree; if the stock is of a different species, he should chop off the tree below the point of the graft. (Nobody has suggested that George Washington chopped down his father’s cherry tree because it was grafted onto a different species. Since George always strove for truth, however, this was, nonetheless, an additional good deed, at least according to some opinions.) As we will see shortly, there is no violation of bal tashchis in cutting down a grafted tree.
Often, even a non-expert can detect if a tree was grafted onto a different species by simply scrutinizing the tree. If the bark somewhere near the bottom of the tree looks very different from the upper part of the tree, this indicates that the upper part of the tree was grafted, possibly onto a different species. Before purchasing a new tree at a nursery, examine the trunk carefully for signs of grafting. If, indeed, this tree is the product of a graft onto a different species, then watering or pruning it violates a Torah law, as I will explain. Furthermore, one may not use a sprinkler to irrigate the rest of the lawn on which the tree stands, if this tree will benefit.
Nectarine trees are susceptible to a host of plant diseases, and, as a result, are usually grafted onto the stock of peach, plum, almond or other trees. It is unclear whether peach and nectarine are halachically considered the same species, but the other species are not the same, according to halacha. Therefore, watering a nectarine tree grafted onto a different species stock probably violates halacha.
By the way, according to halacha, one may plant or maintain different species of trees in close proximity, presumably because grown trees do not look mixed together but stand distinct.
DOES THE PROHIBITION AGAINST GRAFTING APPLY IN CHUTZ LA’ARETZ?
Although most agricultural mitzvos (mitzvos hateluyos ba’aretz), such as terumah, maaser, and shmittah apply only in Eretz Yisrael, some of these mitzvos apply also in chutz la’aretz, such as the mitzvah of orlah, which prohibits using fruit that grows on a tree before it is three years old.
Although the laws of orlah differ when the tree grows in chutz la’aretz, the fruit produced before the tree is three years old is nevertheless prohibited.
Where does kelayim fit into this picture? Of course, some kelayim prohibitions, such as shatnez, cross-breeding animals and lo sacharosh are not agricultural and, therefore, apply equally in Eretz Yisrael and in chutz la’aretz. Among the agricultural prohibitions of kelayim, some apply in chutz la’aretz also, whereas others apply only in Eretz Yisrael.
Planting vegetables and other edible crops together applies only in Eretz Yisrael, grafting trees applies equally in chutz la’aretz and in Eretz Yisrael min hatorah, while planting in a vineyard applies in chutz la’aretz, but only miderabbanan (Kiddushin 39a).
MAY I OWN KELAYIM?
The Gemara (Moed Katan 2b) cites a dispute whether maintaining kelayim in a vineyard (in Eretz Yisrael) is prohibited min hatorah. Rabbi Akiva contends that building a fence to assist the growth of the two different species together violates a Torah law, whereas the Sages contend that it does not (Rashi to Avodah Zarah 64a).
Most poskim conclude that one may not own kelayim in a vineyard, but must remove the plant that is causing kelayim (Shulchan Aruch Yoreh Deah 297:2). The Rambam (Hilchos Kelayim 1:2) paskins that owning kelayim is prohibited only miderabbanan, whereas the Rosh (Hilchos Kelayim #3) prohibits this min hatorah. (We should note that Shu’t Chasam Sofer [Yoreh Deah #282] contends that Tosafos [to Avodah Zarah 64a s.v. Rabbi Akiva] permits owning kelayim.)
WHAT ABOUT OWNING A GRAFTED TREE?
Most poskim assume that one may not own a kelayim tree, just as one may not own kelayim in a vineyard. Furthermore, they contend that this halacha applies, whether the tree is in Eretz Yisrael or in chutz la’aretz (Rosh, Hilchos Kelayim Chapters 1& 3; Pischei Teshuvah, Yoreh Deah 295:2, quoting many poskim).
However, in times past, many observant Jews purchased agricultural properties that contained kelayim trees, and they did not cut down those trees. Was there any justification for their actions? Many halachic responsa discuss what was, apparently, a widespread practice in the eighteenth and nineteenth centuries. Whereas most poskim rule that these Jews violated the halacha, some authorities justify the practice of owning grafted trees, at least in chutz la’aretz (Shu’t Chasam Sofer, Yoreh Deah #288; cf. Aruch Hashulchan, Yoreh Deah 295:17-18). Even these opinions agree that it is preferred to follow the stricter approach and cut down the grafted part of the tree.
I THOUGHT THAT ONE MAY NOT CUT DOWN A FRUIT-BEARING TREE?
Although it is usually prohibited to chop down a tree that bears enough fruit to be profitable, this prohibition does not exist when owning the tree involves a prohibition. Furthermore, bal tashchis, generally, does not exist when one is trying to enhance one’s observance of mitzvos.
Nevertheless, it is preferred to have a non-Jew chop down the tree, since he has no mitzvah of bal tashchis.
DOES THE MITZVAH OF KELAYIM APPLY TO NON-JEWS?
In general, a non-Jew is required to observe only seven mitzvos. However, there are many opinions that require non-Jews to observe certain other mitzvos. The Gemara (Sanhedrin 56b) quotes a dispute concerning whether a non-Jew must observe certain of the kelayim mitzvos. According to the Sages, no aspect of the prohibition of kelayim applies to bnei Noach, whereas Rabbi Elazar contends that they are included in some of the kelayim prohibitions, but not others. Specifically, they are prohibited from mating different animal species and from grafting one species of fruit tree onto another, but they may plant different species together or in a vineyard, and they may wear shatnez.
Why are they included in some prohibitions but not others?
Describing the creation of plants, the Torah says: “And G-d said, ‘The earth shall sprout forth vegetation, herbage that produces seed; edible trees that produce fruit of their own species…’ And the earth produced vegetation, herbage that produces seed of its own species and trees that bear seed-bearing fruit of their own species” (Bereishis 1:11-12).
Reading the pasuk carefully, we see that Hashem ordered only the trees, and not the herbaceous plants, to “produce fruit of their own species.”
Even though the herbage did, in the end, produce “seed of its own species,” this was not because it was commanded. The Gemara derives from other sources that, just as the earth was commanded to keep tree species distinct, so, too, Adam harishon and all his descendants were commanded to keep these species distinct. But since the herbaceous world was never commanded to keep its species distinct, Adam was not commanded concerning this halacha. Therefore, although Jews may not plant different species together, bnei Noach may (Yerushalmi Kelayim 1:7, quoted by Gra, Yoreh Deah 295:2).
WHICH OPINION DO WE FOLLOW?
Do we rule like the Sages that a non-Jew is not included in the prohibition of harkavas ilan, or like Rabbi Elazar, that he is? The Rambam (Hilchos Melachim 10:6) rules like Rabbi Elazar, that a non-Jew may not graft one species of tree onto another, whereas the Ritva (Kiddushin 39a s.v. amar Rabbi Yochanan) and the Shach (Yoreh Deah 297:3) are lenient.
Although we usually follow the Rambam’s opinion, some poskim suggest that we might be able to rule leniently, if only a rabbinic prohibition is involved, such as where the grafted tree exists already and one is not watering or pruning it (Chazon Ish, Kelayim 1:1).
MS. BAKER’S SHAYLAH
I mentioned earlier that a Jew who prunes or waters a kelayim tree violates the Torah prohibition, whether in Eretz Yisrael or in chutz la’aretz. According to most authorities, one may not even own this tree, and one is required to cut down the grafted part. However, since this last prohibition is only miderabbanan, according to most poskim, non-Jews may allow a grafted tree to survive and may even build a fence around it, since they are not required to observe rabbinic prohibitions. (Compare, however, Shu’t Mahari Asad, Yoreh Deah #350 and Shu’t Maharsham 1:179.) Ms. Baker may not water or prune a grafted tree, because that is halachically equivalent to planting it, which is prohibited according to most opinions. In my opinion, she may also not operate her sprinkler system to irrigate her lawn, if the kelayim tree will benefit as a result.
May Ms. Baker ask another non-Jew to water her tree? The poskim dispute whether a non-Jew may ask or hire someone else to violate a mitzvah. Most contend that this is permissible, because the mitzvah of lifnei iveir, causing someone else to violate a mitzvah, does not apply to non-Jews (Tosafos, Avodah Zarah 16b s.v. lenachri). Other authorities (Ginas Veradim, Klal 43) prohibit this, basing themselves on earlier sources that prohibit a ben Noach from violating a transgression that logic tells us to avoid (Rabbeinu Nissim, Introduction to Shas).
MAY WE EAT THE FRUITS OF A GRAFTED TREE?
One may eat the fruits of a grafted tree (Rambam, Hilchos Kelayim 1:7, based on Yerushalmi). One may even take the shoot of a grafted tree and plant it, after it has been severed from the original tree.
SEPARATION OF SPECIES
In all six types of kelayim mentioned above, the general criterion is to avoid the appearance of different species being intermingled.
Concerning this, Rav Hirsch (Vayikra 19:19) writes, “The Great Lawgiver of the world separates the countless numbers of His creations in all their manifold diversity, and assigns to each one of them a separate purpose and a separate form for its purpose.”
In addition, observing the laws of kelayim helps us remember how various species obeyed Hashem’s instructions to remain separate during their creation (the source for some halachos of kelayim, as we saw above). This reminds the contemplative Jew that if the plants heeded Hashem’s word during the Creation, how much more are we obligated to obey all His instructions.
The author thanks Dr. Joshua Klein of the Volcani Institute and Rabbi Shmuel Silinsky for their tremendous assistance in providing horticultural information for this article.