Before us is Mishnah 4 in the fifth chapter of Maseches Kilayim. The Mishnah deals with two matters: a single vine planted in a depression in the ground, and a house standing inside a vineyard.
A vine planted in a winepress or in a crevice:
The Mishnah opens: "Gefen shehi netuah b'gas o v'neka - nosnin lah avodasah, v'zorea es hamosar" - the subject is a single vine planted inside a depression:
"B'gas" - the winepress itself forms a depression in the ground.
"B'neka" - a hole or some other depression in the ground.
"Nosnin lah avodasah" - we set aside for the vine the area needed for its cultivation, which is six tefachim. "V'zorea es hamosar" - the rest of the area of that depression may be sown, even though it is close to the vine.
The view of Rabbi Yosi:
Rabbi Yosi disagrees and rules: "Im ein sham arba amos - lo yavi zera l'sham" - according to him, everything depends on the size of the depression in which the vine is planted:
The area does not measure four amos: one may not sow there at all, and even distancing six tefachim from the vine does not help, since the area is too narrow.
The area does measure four amos: distancing six tefachim from the vine itself is sufficient, and sowing is permitted, since this is a sufficiently wide area.
A house in a vineyard:
The Mishnah then rules: "Bayis shebakerem - zorin b'socho" - a house standing inside a vineyard that is completely closed in by walls and a roof may be sown inside. And even if the vines themselves cover the entire house, this makes no difference, since the house is a domain of its own and an area completely separate from the vineyard.
In summary: in this Mishnah we learned that for a single vine planted in a winepress or in a crevice, we set aside six tefachim for its cultivation and the rest of the area may be sown; and according to Rabbi Yosi, if that place does not measure four amos, one may not sow there at all, even at a distance of six tefachim. We also learned that a house standing inside a vineyard may be sown, even if the vines cover it entirely, because it is a separate domain.