Jerusalem Talmud Kilayim 1:8

משנה: אֵין נוֹטְעִין יֶרֶק בְּתוֹךְ סַדֵּין שֶׁל שִׁיקְמָא אֵין מַרְכִּיבִין פֵּיגָם עַל גַּבֵּי קִידָּה לְבָנָה מִפְּנֵי שֶׁהוּא יֶרֶק בְּאִילָן. אֵין נוֹטְעִין יִיחוּר שֶׁל תְּאֵינָה לְתוֹךְ הֶחָצוּב שֶׁיִּהְיֶה מַקּוֹרוֹ. אֶין תּוֹחְבִין זְמוֹרָה שֶׁל גֶּפֶן לְתוֹךְ הָאֲבַטִּיחַ שֶׁתְּהֵא זוֹרֶקֶת מֵימֵיהָ לְתוֹכוֹ מִפְּנֵי שֶׁהוּא אִילָן בְּיֶרֶק. אֵין נוֹתְנִין זֶרַע דְּלַעַת לְתוֹךְ הֶחָלַמּוּת שֶׁתְּהֵא מְשַׁמְּרָתוֹ מִפְּנֵי שֶׁהוּא יֶרֶק בְּיֶרֶק. MISHNAH: One does not plant vegetables in the stump¹⁵⁰“Anvil.” Sycamores were mainly planted for their wood and cut down regularly. Their stumps do regenerate. of a Sycamore tree, one does not graft rue on white cassia, because that would be vegetable on tree. One does not plant a fig tree shoot into rue¹⁵¹For the determination of חצוב, cf. Peah 2:1, Note 26. so that the latter should cool it¹⁵²Interpretation of Maimonides and R. Isaac Simponti. R. Simson suggests either this translation or “that it serve as a wall around it.”; one does not put a shoot of a vine into a watermelon so that it should supply the shoot with its fluid, because that would be tree on vegetable. One does not put a pumpkin seed into a mallow¹⁵³Identification of Arukh and R. Isaac Simponti. The Italian malva given by these authors means either mallow or marshmallow. I. Löw identifies the plant as bugloss (Anchusa officinalis L.). so that it should protect it, because that would be vegetable on vegetable¹⁵⁴One has to assume that all combinations forbidden here were taken from contemporary agricultural practice..

הלכה: רִבִּי זְכַרְיָה חַתְנֵיהּ דְּרִבִּי לֵוִי בָּעֵי בְּלֹא כָּךְ אֵינוֹ אָסוּר מִשּׁוּם זְרָעִים תַּחַת הַגֶּפֶן. אָמַר רִבִּי יוֹסֵי תִּיפְתָּר בְּמַעֲמִיק שׁוֹרֶשׁ לְמַטָּה מִשְּׁלֹשָׁה טְפָחִים חוּץ לְשִׁשָּׁה. כְּהָדָא דְּתַנֵּי שָׁרְשֵׁי פיאה הַנִּכְנָסִין לְתוֹךְ אַרְבַּע אַמּוֹת שֶׁבְּכֶרֶם. לְמַטָּה מִשְּׁלֹשָׁה טְפָחִים הֲרֵי אֵילּוּ מוּתָּרִין. HALAKHAH: Rebbi Zachariah, son-in-law of Rebbi Levy, asked: Apart from that, is it not forbidden because of seeds under a vine¹⁵⁵As indicated in the Introduction, vineyards have particularly strict rules, based on Deut. 22:9. These rules are spelled out in later Chapters of the Tractate. The questioner is of the opinion that planting a shoot of vine in a water melon would be forbidden even if in general trees on vegetables were permitted.? Rebbi Yose said, explain it if he sets its root¹⁵⁶Meaning the watermelon, that the root of the new vine will grow down there, not that the shoot is set into a watermelon. down more than three hand-breadths¹⁵⁷A hand-breadth is one sixth of a cubit., distant more than six hand-breadths [from the vine], following what was stated¹⁵⁸Tosephta Kilaim 4:11.: “roots of madder¹⁵⁹Following the reading of R. Solomon Adani in מלאכת שלמה from his manuscripts: פוּאָה Rubia tinctorum L., an industrial plant whose roots were used to produce dye. Hence, the roots of the plant are more important for כלאים than the parts above ground. This is the reading of R. Saul Lieberman; it is offered for ease of translation.
However, the few manuscript sources at our disposal all read פֵּיאָה, and one must explain the text with this reading. (As Lieberman correctly notes, the attempt by R. Moses Margalit is incomprehensible.) In Tractates Kilaim and Eruvin, the word פֵּיאָה does not have the meaning “corner” as in Tractate Peah, but means a wire or string strung as a symbolic fence around a field to separate it from the next one, or around a town to make it a “walled” town for the rules of Sabbath. Now, it is stated in Mishnah and Tosephta of Chapter 4 that a solid wall permits one to plant vegetables on one side and vines on the other. This clearly is inadmissible for a peah-fence; one may not plant vines within four cubits of such a symbolic fence. Then the Tosephta states that even in this case the roots that enter from the outside do not cause kilaim if they are at a depth of at least half a cubit. that enter within four cubits of a vineyard are permitted below three hand-breadths.”