(Mishnah): All species of seeds may not planted in one vegetable bed, but all species of vegetables may. Mustard and small peas are considered seeds; large peas are a type of vegetable.

If a border wall had been a Tefach tall and it was reduced, it remains valid since it began valid.

If a furrow or a stream were a Tefach deep, one may plant three types of seeds in them - one on each side and one in the middle.

(Gemara): 'All species of seeds...mustard and small peas are considered seeds' - even if he planted them to eat when still moist, it's not the norm and they are considered seeds that may not be planted with several other seeds in a bed.

Large peas and Egyptian beans that were planted for their seeds may not be planted with several other seeds in a bed. If he planted them to eat, he may plant them in a bed.

Other field vegetables and garden vegetables that are not eaten, even if he planted them for their seeds, they may be planted with several other seeds in a bed.

The Mishnah taught that if a border wall had been a Tefach tall and it was reduced, it remains valid since it began valid. R. Imi said that it still permits allowing the seeds that he had planted earlier, but to plant new would be prohibited.

If he transgressed and planted there, since these are permitted, those are permitted.

Question (R. Yirmiyah): It's understandable that if the second ones (planted after the border was reduced) are uprooted, the first ones are permitted; but if the first ones are uprooted, what is the status of the second ones?

Answer (Mishnah in Maseches Keilim): A bed that had its two lengths removed and new lengths were made without changing the holes of the horizontal bars, it remains Tamei (as the old lengths could still be returned). Therefore, if the new lengths broke, it remains Tamei, but if the old lengths or widths broke, it is Tahor (as the old bed is now irreparable). This shows that if the second plantings were uprooted, the first ones are permitted; if the first plantings were uprooted, the second ones are prohibited.

(R. Yona): R. Zeira and R. Imi both spoke in the name of R. Yochanan (that there's a difference between a fence and a border) - one said that one may plant two types of seeds on either side of a 10 Tefach-tall fence, but one may not plant them on either side of a border (since it's only a Tefach wide). The other one said that a border that was reduced is valid (meaning that seeds on either side are not Kilayim). From this we can deduce that if there was a fence that was reduced, it is invalid. However, it is unclear who said each statement...

Proof: From the statement of R. Yosi/ R. Zeira citing R. Yochanan that one may plant two types of seeds on either side of a fence but one may not plant them on either side of a border...

This shows that it was R. Imi who said that a border that was reduced is valid; however, a fence that was reduced is invalid.

(R. Yosi): We could have also learned these two laws in the Mishnayos (of this Maseches) - A) 'A border that was reduced is valid' - this means that a fence that was reduced is invalid (otherwise it should have appeared earlier in the second Perek amongst the laws of fences and said that if they are reduced, they are valid).

B) 'One may plant (two species) close to a fence (one on either side)'. This was taught earlier in the Mishnah (Menachos 40/Kilayim Perek 2 Mishnah 6), "One may plant them close to fallow land, plowed land, a stone fence, a (4 Tefach-wide) path, a 10 Tefach high fence".

And the other part of that law of R. Yochanan is that 'one may not plant two species on either side of a border'. This was also taught in the Mishnah, when it said, "If a furrow or a stream were a Tefach deep, one may plant three types of seeds in them - one on each side and one in the middle." If it would be permitted to plant near a border, he should plant several rows on either side of the furrow (with the furrow separating between them).

Rebuttal (Chevraya to R. Shmuel bar Avin): When the Mishnah didn't allow planting rows on each side of the furrow, it was when he planted on the very top edge of the border (thereby allowing only one species to be planted).

Rejection (R. Shmuel bar Avin to Chevraya): If so, why wouldn't he uproot the stalk that he planted on the very top edge of the border and instead plant several rows on each side.