As we learned in the Mishna on yesterday’s daf, the second perek of Massekhet Bava Batra focuses on keeping neighbors from damaging each other’s property by limiting certain activities within their own property.
Aside from the examples enumerated in the Mishna, the Gemara quotes a baraita that obligates a neighbor to keep
- water in which flax is soaked away from his neighbor’s vegetables
- leeks away from his neighbor’s onions, and
- mustard plants away from his neighbor’s bees.
The problem with leeks and onions growing close to each other rests in the similarities that they share. These two vegetables, leeks – kereisha or allium porrum – and onions – betzalim or allium cepa – not only look similar, but they belong to the same botanical family. Due to their close relationship, if they are planted close to each other, insects that ordinarily pollinate such plants may inadvertently cross-pollinate them, producing non-fertile plants. Therefore those leeks and onions that are being grown for their seeds will be worthless.
With regard to mustard and bees, mustard plants are common in Israel, and their colorful flowers attract bees to them. Rashi explains that the bees may eat the sharp mustard, which may then lead them to devour their own honey, causing a loss to the beekeeper.
Rabbi Yosei disagrees with this last halakha, arguing that the owner of the mustard plants can argue that as much as his plants may cause damage to the bees, similarly the bees cause damage to his plants. Since both parties are causing damage to one another, we cannot make demands on one of them rather than on the other. This position is rejected by the Tanna Kamma, since the damage that is done to the leaves is minimal – birds and other insects do more damage than bees – and the bees cannot reach the mustard seeds themselves.