Mishnayos Sheviis Perek 6 Mishnah 3

בצלים שירדו עליהם גשמים – onions of the Sixth [Year] which entered into the Seventh [Year, and rain fell upon them and they grew, if the leaves blackened with the knowledge that they grew and added, and the growth of the Seventh Year came and nullified the essence, even though it is a lot. But if the leaves became green, they we go and they wither and it is not from the Land [of Israel] that they increased.

אם יכולין ליתלש בעלין – it is the manner of onions when they are compee that leave on their own from the land and are easy to detach, and if the leaves are strong, and when you grab hold of them, you are able to detach the onions from the ground, then they have certainly grown during the Seventh Year.

כנגד כן למוצאי שביעית מותרים – we are not speaking about onions of the Seventh Year that went out to the aftermath of the Seventh Year, fo we ae not lenient with them all that much, for the permitted growth of a little bit will raise the prohibition, but the ending clause [of the Mishnah] also speaks regarding onions of the Sixth Year that were uprooted in the Sixth Year and then return and were replanted in the Seventh Year, and after they grew a little bit in the Seventh Year, he uprooted them and replanted them in the Eighth Year, and because they had grown already in the Sixth Year, they did n’t add even a little bit in the Seventh Year, and they were prohibited, as when they returned and added a little bit in the Eighth Year, he retracted that permission and nullified the minute prohibition, for also that of the Sixth Year assisted to nullify it the end of permitted growh. But the Halakha is not according to Rabbi Hanina ben Antigonos.