04 –  Seed Kilayim and Vineyard Kilayim

01. The Prohibition Against Seed Kilayim

The Torah prohibits sowing two types of seed together in a field in Eretz Yisrael. Each type must be sown on its own, as it says: “You shall keep My statutes… You shall not sow your field with kilayim” (Vayikra 19:19). The word kilayim means “mixture.” This prohibition includes edible grains, legumes, and vegetables. Plant species grown for ornamentation or medicine, however, are not included.

The prohibition against seed kilayim applies to annual crops: grain, legumes, and vegetables. There is no prohibition against planting different species of trees together, nor against planting trees together with an annual crop. Even when trees are intermingled, their size makes it clear that each tree has its own distinct place. The annual crops planted among them likewise have their own place, since trees grow upward and their roots spread far outward, leaving room for the annual crop to grow among them.

One who waters, fertilizes, weeds, or otherwise assists the growth of kilayim violates a Torah prohibition punishable by lashes. Even when kilayim grew on its own in his field, as long as he wants them there – or it appears as though he wants them there – he must uproot them, for one may not maintain kilayim in one’s field (MT, Laws of Kilayim 1:1–3).

If one deliberately sowed kilayim, the produce may nevertheless be eaten. The prohibition is against sowing and cultivating kilayim; eating what grows from them is not prohibited (MT, Laws of Kilayim 1:7). Only with vineyard kilayim does the resulting produce become forbidden to eat.

The prohibition against seed kilayim applies in Eretz Yisrael. Even on land owned by a gentile, a Jew may not sow kilayim. In the Diaspora, however, a Jew may sow seed kilayim, because the verse speaks of “your field,” and only Eretz Yisrael is considered “your field” for this purpose. The Sages did not prohibit seed kilayim there either; they prohibited only vineyard kilayim in the Diaspora, because it is more severe: one may neither eat its produce nor derive benefit from it (see below, section 7).

In Eretz Yisrael, it is also prohibited to sow two species together in a pot. If the pot is perforated, it is considered connected to the ground, and the prohibition applies by Torah law. If it is not perforated, it is detached from the ground, and the prohibition is rabbinic.^[1]

02. The Concern of Marit Ayin in Seed Kilayim

By Torah law, seed kilayim is prohibited when a person sows two species together or willingly maintains them together. If they grew in his field without his wanting them, he has not violated a Torah prohibition. Nevertheless, because of marit ayin, the appearance of wrongdoing, the Sages prohibited a field owner from leaving kilayim in his field even when he does not want them there. Since the field is open and visible to all, passersby may think that the owner does not care about observing the mitzvot, and this would desecrate God’s name.

Therefore, if one wants to sow his field with wheat and finds that barley seeds have become mixed in with the wheat, he may do so only if the barley remains below a certain threshold. If the barley is not enough to produce one twenty-fourth of the field’s yield – 1/24, or 4.16% – he may sow the mixture as it is. With such a small amount, there is no concern for marit ayin, since anyone who sees the field will understand that the barley is growing there against the owner’s will.

Although one may not intentionally sow even a single barley seed in a wheat field, this applies only when the barley was deliberately added. If one intentionally mixed even one barley seed into the wheat, he may not sow the wheat unless he first removes the barley seed. If, however, the barley became mixed in unintentionally, he does not want it there, and removing it would be burdensome, he may sow the mixture as it is, provided the barley is less than one twenty-fourth of what will grow in the field. At such a small proportion, there is no concern for marit ayin, since anyone who sees the field will understand that the barley is growing there against the owner’s will. If the barley is enough to produce one twenty-fourth of the field’s yield, he must either reduce the barley or add wheat until he is certain that the barley will produce less than one twenty-fourth of the growth in the field.

The same rule governs a field that was sown with one species and later has another species growing alongside it. The determining factor is whether he wants the second species to remain. If he does, the mixture is kilayim, and he must uproot the second species entirely. If he does not want it there, and it makes up less than one twenty-fourth of the field’s growth, he need not reduce it. If it reaches one twenty-fourth, he must reduce it until it is less than that amount.^[2]

Because this mitzva is important and those who violate it cause a grave desecration of God’s name, every year on Rosh Ḥodesh Adar, when grain and vegetables were beginning to sprout, the agents of the beit din would urge the Jewish people to be careful about kilayim (Mishna, Shekalim 1:1).

On the fifteenth of Adar, the agents of the beit din would inspect the fields. If they found kilayim, they would uproot the minority species and place it before the owner’s animals. The field owners benefited twice: their fields were weeded, and their animals were fed. They therefore stopped bothering to remove the kilayim themselves. The Sages then enacted that the agents would uproot the kilayim and leave it on the roads, where any animal could eat it. Still, because the field owners were happy that their fields had been weeded, they did not bother to uproot the kilayim. When even this did not solve the problem, since owners still benefited from the weeding, the Sages enacted that the agents of the beit din would declare everything growing in any field where kilayim was found ownerless. From then on, field owners took care to avoid kilayim (Mo’ed Katan 6b). Once the agents of the beit din declared the kilayim ownerless, the field owner no longer violated the prohibition because of it, since the prohibition against maintaining kilayim does not apply to ownerless growth.

03. The Required Separations for Seed Kilayim

The basic principle in the laws of seed kilayim is that two species may be planted near one another when they remain visibly distinct, but not when they appear mixed together. The larger the field, the greater the required separation, so that the distinction between the species remains recognizable. The required separation also depends on the density, size, and length of the plants’ leaves: grain, whose stalks grow tall, requires a greater separation, while vegetables generally require a smaller one, except for vegetables with especially large leaves.

Vegetables: By Torah law, one must leave one tefaḥ – approximately 8 cm – between one vegetable species and another. The Sages extended the required separation to one and a half tefaḥim – approximately 12 cm. If that distance was left between the two species, there is no prohibition against kilayim even if their branches later grow until they touch, since the stems emerging from the ground remain properly separated. There are a few exceptions, such as gourds, whose leaves are especially large and tend to intertwine with neighboring species. In such cases, one must ensure that the leaves of the two species do not touch. These rules apply to beds in a garden. Two vegetable fields, however, must be separated by a square area one ama by one ama – approximately half a meter by half a meter. Along the rest of the boundary between the fields, it is proper to leave a gap of one tefaḥ.^[3]

Grain: Since grain is normally sown over large areas, greater separation is required. By Torah law, the required distance is one ama. The Sages, however, ruled that this distance is adequate only for small plantings less than one ama wide. For grain sown in medium-sized plots, known as a meishar, whose width is at least one ama, the separating area must begin with a square of two amot by two amot – approximately one meter by one meter – and may then taper diagonally, as illustrated below, until only a minimal gap remains between the fields.

When grain is sown in large fields, as is usual, the required separation is a beit rova, a square of about five meters by five meters. Along the rest of the boundary, it is proper to leave a one-ama gap running the length of the two fields.^[4]

Authorities disagree whether legumes are treated like grain or like vegetables. Therefore, one must leave one ama between the two plantings, regardless of the field’s size.^[5] When grain is sown next to vegetables or legumes, or vegetables are sown next to legumes, the required separations are more complex and depend on the size of the field. In any case, the requirement is no stricter than for grain.

If a partition ten tefaḥim high – approximately 80 cm – stands between two fields, no further separation is needed. This is true even of a reed partition, provided that no gap between reeds exceeds three tefaḥim; the partition itself separates the fields. Even if the roots of the two species are known to intertwine underground, there is no kilayim prohibition so long as the partition creates a visible separation. Similarly, a road four amot wide – about 1.84 meters – or a plowed strip of the same width separates the fields, so the large five-by-five-meter beit rova separation is not required.

04. Vineyard Kilayim: A Distinct and Stricter Prohibition

Although vineyard kilayim can be viewed as a particular case of seed kilayim, in practice it has halakhot of its own. This shows most vividly in the produce. Seed kilayim prohibits the sowing, but the crops that grow may still be eaten and used; what grows from vineyard kilayim, by contrast, is forbidden to eat and even to derive benefit from.

One may not sow grain or vegetables alongside grapevines, nor may one plant a grapevine alongside grain or vegetables. If one did so, both crops become forbidden; one may neither eat them nor derive benefit from them, as it says: “You shall not sow your vineyard with kilayim, lest the full yield – the seed you sow and the produce of the vineyard – become consecrated” (Devarim 22:9). In this context, tikdash means that the produce is consecrated for destruction – forbidden for any benefit. “The full yield of the seed you sow” refers to the grain or vegetable, while “the produce of the vineyard” refers to the grapes. Even the grain’s straw and the vines’ wood become forbidden; they must be burned or otherwise destroyed so that no one mistakenly benefits from them (see above, chapter 2, note 3). Because one may not derive benefit from them even as they are being destroyed, one may not burn them to heat an oven or stove (MT, Laws of Kilayim 5:7). The prohibition of vineyard kilayim applies by Torah law in Eretz Yisrael and by rabbinic law in the Diaspora (see below, section 7).

By Torah law, the prohibition of vineyard kilayim applies when grapevines grow alongside the five grain species, legumes, or vegetables. It does not apply, however, to tree species, even small ones. As a rule, any plant whose berakha is ha-etz is not included in the prohibition of vineyard kilayim, while any plant whose berakha is ha-adama is included (see above, 2:8).

This includes spices over which ha-adama is not recited in practice, since they are not eaten on their own (Peninei Halakha: Berakhot 8:14). If they are plant species whose berakha would be ha-adama if they were eaten on their own, they are included in the prohibition of vineyard kilayim.

The Sages also extended the prohibition to grasses and vegetables commonly used as animal fodder. Plants that are not commonly fed even to animals are not included in the prohibition (Levush YD 296:2).

Authorities disagree about plants grown for fragrance. Some authorities prohibit them rabbinically, while others permit them. In practice, it is best to be stringent, but one who wishes to be lenient may do so. Ornamental plants, by contrast, are not prohibited. Therefore, one may plant grass and flowers beneath a grapevine, provided they are not commonly fed to animals, even if they also have medicinal uses.^[6]

05. When the Produce Becomes Forbidden

The prohibition of vineyard kilayim includes not only sowing the forbidden mixture but also maintaining it (Mishna, Kilayim 8:1). Thus, even if a person did not sow grain in his vineyard, if even a single grain stalk grows there, he must act quickly to destroy it, because one may not maintain kilayim in a vineyard.

Sowing and maintaining differ, however, in when the produce becomes forbidden. If one sows a grain stalk in his vineyard, the stalk and the surrounding vines become forbidden for benefit as soon as it takes root. If, however, one merely finds a grain stalk that grew in his vineyard, it and the vines become forbidden for benefit only if it continues to grow by one part in two hundred. Nevertheless, he must destroy it immediately, because even one who is negligent and maintains it for even a moment violates the prohibition (Mishna, Kilayim 5:6; Pesaḥim 25a; MT, Laws of Kilayim 5:21–22; 6:1).^[7]

When do the vines become forbidden for benefit? Only when grapes are present on the vines and are still growing and ripening. This period begins when the grapes reach the boser stage, meaning that their form is recognizable and they are at least the size of a white bean, and it continues until the grapes are fully ripe. If there are no grapes in the vineyard, or if the grapes have either not yet reached the size of a white bean or have already fully ripened, grain or vegetables growing nearby do not render the vines forbidden for benefit. The grain or vegetables themselves, however, do become forbidden.

When does the grain become forbidden? From the time it takes root in the ground until the kernels fully ripen. Therefore, if the grain has already finished ripening and a vine bearing grapes at the forbidden stage is bent over it, the entire vine becomes forbidden, but the grain does not become forbidden (Mishna, Kilayim 7:7).^[8]

If the wind bent a person’s vine over his grain, he must separate them immediately. If there is concern that they will become mixed again, he must cut the vine branches or erect a fence to prevent it from happening again. If he was negligent and they remained mixed until one of the two increased by one part in two hundred, they become forbidden. If, however, circumstances beyond his control kept him from separating them in time, they do not become forbidden (Mishna, Kilayim 7:7; R. Yitzḥak b. Malki Tzedek and R. Shimshon to Mishna, Kilayim 7:7; MT, Laws of Kilayim 5:11; Kesef Mishneh and Mahari Kurkus to MT, Laws of Kilayim 5:11).

A person cannot render someone else’s property forbidden. Therefore, if one caused his vine to spread over another person’s grain, his vine becomes forbidden, but the other person’s grain remains permitted. If he caused another person’s vine to spread over his own grain, his grain becomes forbidden, but the other person’s vine remains permitted. If he caused one person’s vine to spread over another person’s grain, both remain permitted. However, as soon as the owner of either the vine or the grain becomes aware of the kilayim, he must act quickly to separate them. If he is negligent until one of them increases by one part in two hundred, his own portion also becomes forbidden.

The person who actively mixed the kilayim by hand is treated more stringently: for him, even property that is not his becomes forbidden. Moreover, if a person passes by another person’s vineyard, sees grain stalks growing there, and knows that the owner wants them to remain, he must uproot them. Similarly, a worker employed there must uproot the kilayim. If they do not do so, the vine and grain that grew there become forbidden to them for benefit. The vineyard owner, however, has not violated the prohibition. Only once he learns of the kilayim must he act quickly to uproot the grain stalks. If he is then negligent and they continue growing by one part in two hundred, they become forbidden to him and to all Jews (Mishna, Kilayim 7:4; MT, Laws of Kilayim 5:8–9, 21; Taz YD 296:3).

06. Required Distances for Vineyard Kilayim

The mitzva of kilayim requires that grain and vegetable species remain separate from grapevines. The Torah gave the Sages authority to determine, according to their judgment, what is considered mixed and what is not. What the Sages define as a prohibited mixture is therefore included in the Torah prohibition. There are three main situations in the laws of vineyard kilayim, listed here in ascending order of severity: 1) near a single vine; 2) near a vineyard; and 3) inside a vineyard.

A single vine: One who wishes to sow grain or vegetables near a single vine must keep them six generous tefaḥim away, approximately 47 cm. This is the area needed for the vine’s bed and the workspace around it. Grain or vegetables may not grow beneath the vine’s canes either. Thus, if a grain stalk grew beneath one of the canes, leaves, or clusters growing from the vine – even one hundred amot from the vine’s trunk – and the owner was negligent and did not uproot it, the stalk and the entire vine become forbidden for benefit, as explained above in section 2. If there is doubt whether the stalk is beneath the vine, its position is determined by a plumb line. Since vine canes often extend over a large area, one must ensure that no grain or vegetables grow beneath them at any point along their length.

Vines are commonly trained along poles or cords, with the canes expected to grow along them. The Sages therefore decreed that grain or vegetables may not grow even beneath the part of a pole or cord that the cane has not yet reached, since the cane is expected to extend there. After the fact, however, as long as the grain or vegetables were not actually beneath the vine itself, they do not become forbidden (MT, Laws of Kilayim 6:11–12, 15).

A vineyard is a grapevine planting arranged precisely according to the accepted method of cultivation. Since a vineyard has halakhic significance, one who sows grain or vegetables within four amot of it is considered to have sown them together with the vineyard, thereby violating the prohibition of kilayim. This distance was set at four amot, approximately 188 cm, because that was the space needed for vineyard work in earlier times. Vineyards were plowed with oxen, and at harvest time the grapes were brought from the vineyard to market by cart; both the oxen and the carts required this working space.

For vines to be considered a vineyard, they must form at least one of the following arrangements: two facing rows, with three vines in each row, as follows:

or five vines arranged as “two opposite two, with one extending like a tail.” Rambam illustrates this second arrangement as follows:

R. Shimshon illustrates it this way:

If the vines do not form straight rows, even if there are many of them, they are treated a

individual vines.^[9]

If one sows grain or vegetables within four amot of a vineyard, the portion of the vineyard equivalent to a small vineyard becomes forbidden – that is, the five vines closest to the kilayim, arranged in vineyard formation. If there are additional vines within four amot of the kilayim in any direction, they too become forbidden. One must also be careful with any vine cane that extends beyond the four-ama zone surrounding the vineyard. It is treated like a single vine, so grain or vegetables may not grow beneath it; if they do, both that vine and everything growing beneath the cane become forbidden.

An aris has the same status as a vineyard. An aris is formed by at least five vines planted in a straight row and trained along poles or wires, allowing them to receive more sun and air and produce more abundant, higher-quality grapes. If the kilayim are within four amot of the aris – whether near the vine trunks or near the poles or wires on which the vines are trained – the five vines facing the kilayim become forbidden.

A fence ten tefaḥim high, approximately 80 cm, separates the vineyard from the field. Once such a fence stands between them, one may sow grain or vegetables on the other side without any additional distance (MT, Laws of Kilayim 7:15). This is true even if the vine’s roots extend beneath the grain, because vineyard kilayim is defined by the visible appearance of mixture, not by the underground spread of roots. Since the fence makes the vineyard and field appear separate, the plants are not considered mixed.

Inside the vineyard: If one sowed kilayim inside a vineyard, or if kilayim grew there on its own and the owner was negligent and did not uproot it, the mixture is more apparent because it is inside the vineyard itself, and its laws are therefore far more severe. The affected area is measured by the reach of the roots’ nourishment: sixteen amot in every direction, plus an additional four amot for the vineyard’s work area. Thus, every vine within less than twenty amot of the kilayim becomes forbidden for benefit (MT, Laws of Kilayim 6:1–2).

07. The Diaspora and Kilayim of Non-Jews

The Torah prohibition of seed kilayim and vineyard kilayim applies only in Eretz Yisrael. Regarding seed kilayim, the verse states: “You shall keep My statutes… You shall not sow your field with kilayim…” (Vayikra 19:19). Regarding vineyard kilayim, it states: “You shall not sow your vineyard with kilayim” (Devarim 22:9). The terms “your field” and “your vineyard” refer to the field and vineyard of the Jewish people, which are in Eretz Yisrael. Nevertheless, because vineyard kilayim is especially severe – its produce is forbidden both to eat and to derive benefit from – the Sages extended the prohibition to the Diaspora as well. They established, however, that in the Diaspora the prohibition applies only to cases that all authorities agree are forbidden by Torah law in Eretz Yisrael, both with respect to sowing and with respect to benefit (Kiddushin 39a).

Therefore, in the Diaspora, vineyard kilayim is prohibited only when one sows at one time a grape seed together with two other seed species that are themselves kilayim with one another – for example, two types of grain, two types of vegetables, or one vegetable species together with one grain species.

Although in Eretz Yisrael the Torah prohibition of vineyard kilayim applies even when one sows a single grain stalk next to a grapevine, and one who knowingly eats what grows there is liable for lashes, one is liable for sowing vineyard kilayim only in the narrower case: when he sows a grape seed together with two seed species that are kilayim with one another. Therefore, in the Diaspora, both the prohibition of sowing vineyard kilayim and the prohibition of deriving benefit from what grows apply only in that case. One may, however, sow grain in his vineyard in the Diaspora and eat what grows there (Rema YD 296:69).^[10]

Although a non-Jew may sow kilayim in his vineyard in Eretz Yisrael, a Jew may not instruct him to do so (MT, Laws of Kilayim 8:13). Furthermore, by Torah law, a Jew may not derive benefit from grapes, grain, or vegetables that grew as kilayim in a non-Jew’s vineyard (Tosafot, Kiddushin 36b, s.v. kol; Rosh). Therefore, one may not buy grapes or vegetables from non-Jews near the vineyards where they were grown, since they may have been grown in violation of the prohibition. If one transgressed and bought them, he may not derive benefit from the produce. Since the doubt arose while the produce was still near its fixed place of origin, it is forbidden both to eat and to derive benefit from.

If, however, one buys in the market or in stores grapes or vegetables grown by non-Jews, then the doubt arose only after the produce had already separated from its fixed place. We therefore follow the majority, and the produce may be eaten. This ruling applies be-di’avad – for example, when one has already bought the produce and does not know its status, or when one is in a place with no kashrut-certified stores, and reaching such a store would require significant effort. If, however, there is a kashrut-certified store, one must avoid the doubt and buy there. Even when the concern is very remote, one must avoid entering a doubtful situation whenever possible. In addition, it is a mitzva to strengthen those who are careful in matters of kashrut. Moreover, when produce bears kashrut certification, terumot and ma’asrot will also have been separated properly, as explained above, 2:11.^[11]

08. The Reason for the Mitzva

The prohibition of vineyard kilayim is unique. In addition to the prohibition against mixing grain or vegetables with a grapevine, the produce that grows from such a mixture is itself forbidden, both to eat and to derive benefit from, as it says: “You shall not sow your vineyard with kilayim, lest the full yield – the seed you sow and the produce of the vineyard – become consecrated” (Devarim 22:9). Here, “become consecrated” does not refer to positive holiness. It means that the produce has been designated and set aside for a particular purpose. Usually, such designation is holy and exalted; at times, however, people dedicate themselves to sin, as in the case of a prostitute, who is called a kedesha (Bereishit 38:21). So too, the fruit of vineyard kilayim, having been set apart through sin, becomes consecrated to impurity and is forbidden to the entire Jewish people.

Vineyard kilayim may be treated so severely because it involves the vineyard, and wine has extraordinary power – for good and for harm. On the one hand, song and blessing are recited over wine. On the other hand, it can degrade a person and cast him into the depths of sin. For this reason, a special mitzva of nezirut was established in relation to wine: one who fears that wine may pull his heart toward evil, or hinder his growth in holiness, takes a vow to abstain from it. Indeed, an entire tractate of the Talmud is devoted to this subject: Nazir.

Since wine can sway a person’s judgment, the Torah forbids kohanim to drink wine while serving in the Temple. Similarly, one who has drunk wine may not pray (Peninei Halakha: Prayer 5:11). This same concern helps explain why the Torah treated vineyard kilayim more severely than other forms of kilayim: anything connected to wine requires special care. Wine should be used for the joy of a mitzva, not for unrestrained indulgence or escape from responsibility (see Peninei Halakha: Berakhot 7:1–2).

There is another dimension as well: grain, legumes, and vegetables are essential to human survival. Although eating them does not involve especially intense desire, a person cannot live without them. Therefore, one must work diligently to cultivate them and eat them regularly. Wine, by contrast, is not necessary for survival, but it brings great joy and is meant to serve the joy of a mitzva. This helps explain why blurring the boundary between these two categories is dangerous. If a person treats wine like grain, drinking it as a regular staple, he may become enslaved to his desire and fall into alcoholism. Even if he does not become addicted, excessive daily drinking causes wine to lose its special role in the joy of a mitzva. Conversely, if a person treats grain like a vine, as though it were not essential, he will become lazy, and thorns will grow in his field instead of grain (see Shemen Ra’anan, p. 333, citing Maran Rav Kook).