Kilayim 5:6-7

Kilayim 5:6

If a person sees vegetables growing in his vineyard and he says that he will remove them when he gets there, it is permitted (rather than prohibited because of mixed species). If he said he would remove them on his return, then if the vegetables increase by 1/200 in the interim, it becomes prohibited. (His procrastination in removing the vegetables suggests that he in fact values their presence, which renders them kilayim.)

Kilayim 5:7

If a person was walking through his vineyard and he accidentally dropped some seeds, or they fell while he was while fertilizing or watering the field, or while planting, or the wind blew them behind him (so that he didn’t notice), the vegetable that grows is unintentional and permitted. If the wind blew the seeds in front of him (so that he noticed), it’s forbidden because of mixed species. Rabbi Akiva says he must plow up a crop that grows in blades and he must beat a crop that grows in ears. If it actually spouted grain, it must be burned.