Related for Terumot 9:13

One who plants terumah flax -- [if he discovers it] before it has grown a third [of its full size], he must overturn the soil, but if it has grown a third [or more], he lets it remain, the words of Rabbi Meir. Rabbi Yehuda says, if [he had planted it] unwittingly, before it has grown [a third], he overturns the soil, but if it has grown a third [or more], he lets it remain, but if [he had planted it] intentionally, whether less than a third or a third, he overturns the soil.

One who pulls weeds among [terumah] leeks with a Gentile (alt., "with a Samaritan"), even though its produce is untithed, he may not* eat casually among the produce [of leeks]. [*Note: Ter. 9:7 has "he may eat casually."] Rabbi Shimon ben Elazar says, right after shevi'it (the seventh year of the agricultural cycle, when fields lie fallow), he is permitted [to eat casually if he is weeding alongside] a Jew.