Kommentar zu Sheviit 5:5

רבי יהודה אומר מיד – and even though that with the rest of the vegetables, Rabbi Yehuda admits that it is prohibited until he makes something in a similar manner; the LOF (plant with edible leaves and root of the onion species) since he must uproot it, according to the School of Shammai with a wooden rake, and according to the School of Hillel with metal spade , there is no way to uproot it in the Seventh Year other than through a change of form, therefore, on the aftermath of the Seventh Year, there is no prohibition found on hand, and because of this, it is permitted immediately, but regarding vegetation where they did not decree that they should not detach it because its path is found at hand, it is also forbidden during the Eighth Year, therefore, it is prohibited until he does something in a similar manner.

From when may one buy luf after the seventh year? Rabbi Judah says: immediately. But the sages say: [only] after the new crop has appeared. Our mishnah discusses when a person can begin to sell luf after the seventh year is over without people suspecting that the luf was sabbatical year produce. According to Rabbi Judah, he may begin to sell it immediately. Although, as we shall see when it comes to vegetables, anything bought after the seventh year must be treated like seventh year produce until enough time has passed for new vegetables to grow, with luf they were less stringent because we can assume that luf in the eighth year is actually from the sixth year. The other rabbis hold that luf is treated the same way as other vegetables it too is forbidden until there has been enough time for a new crop to appear.

מירבה (בו) החדש – in the Jerusalem [Talmud] it explains that this is from Passover onwards. And the Halakha is according to the Sages.