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).
[9]. It is clear that the Torah intended the Sages to define the parameters of the prohibition. The requirement to distance grain or vegetables four amot from a vineyard, which has the status of Torah law, was established by the Sages because vineyard work – including plowing with cattle and transporting the crop by cart – required four amot. The additional stringency regarding grain that grows inside a vineyard or within the empty space surrounding a vineyard, however, is rabbinic.
Regarding a single vine, Sifrei, Ki Tetze §230, Ramban, and Ran explain that the requirement to distance grain or vegetables six tefaḥim from a single vine is by Torah law. In other words, the measure established by the Sages for the work area of a single vine is binding by Torah law. By contrast, several Rishonim imply that the prohibition of vineyard kilayim applies only in an actual vineyard, and that the entire requirement to distance grain or vegetables from a single vine is rabbinic (She’iltot; Sefer ha-Ḥinukh §548). See the Herḥavot.
All measures of kilayim stated in tefaḥim use generous tefaḥim, as explained in SA YD 296:68. In the Herḥavot to Peninei Halakha: Sukkot 2:1, note 11, it is explained that we follow the view of Rashba, cited in SHT 363:60, that a generous tefaḥ adds approximately 1/48. Thus, an ama of six tefaḥim, normally 45.6 cm, is in practice 46.55 cm, which we rounded to 47 cm. Four amot were therefore rounded to 188 cm.
The Sages said that the distance between vineyard rows is between four and eight amot. Rambam implies that the same applies between one vine and another in the same row. Today, the accepted practice is to leave slightly more than four amot between vine rows, but only about three amot between vines in the same row. It seems that since this is now the optimal method of cultivation, such a planting is considered a vineyard. My teacher, R. Yisraeli, writes similarly. He adds that according to Rosh, even in the past there was no objection to planting the vines within a row at a distance of less than four amot from one another (Eretz Ḥemda, vol. 2, 7:1–3).
