Kilayim 6:2-3

Kilayim 6:2

Let’s say that an aris sticks out from a raised platform. Rabbi Eliezer ben Yaakov says that if the owner can gather all the grapes while standing on the ground, then it is the same as one actually on the ground and a space of four cubits (six feet) must be left; if not, only the land immediately adjacent to the aris is prohibited and the rest may be planted. Rabbi Eliezer says that if one plants one row of vines on the ground and another on a raised platform, if the latter is ten handbreadths above the ground, they do not combine to form a vineyard; within ten handbreadths, they do.

Kilayim 6:3

If one trains a grapevine over part of a trellis, he may not plant vegetables beneath the other part (because it’s all considered as one). If he did do so, it is not rendered prohibited. However, if the vines grow and extend over the vegetables, the latter are then rendered prohibited. The same is true if one trains vines over part of a non-fruit tree.