(Mishnah): One may not sow mustard or Charia (saffron) close to a grain field, but one may sow them close to a vegetable field. One may plant them close to fallow land, plowed land, a stone fence, a (4 Tefach-wide) path, a 10 Tefach high fence, a 10 Tefach deep furrow that is 4 Tefachim wide, a tree that forms a covering over the ground and a stone that is 10 Tefachim tall and 4 Tefachim wide.

(Gemara): 'One may not sow...'. What is Charia? Murika (saffron).

When the Mishnah taught - 'One may not sow close', it must be understood as meaning that one may not surround a grain field with a row of mustard; but one may sow a row of mustard close to a grain field.

The Mishnah (that doesn't allow sowing near grain but does allow near vegetables) is from R. Yehuda, as the Baraisa taught...

(R. Meir): One may not surround other species with mustard or saffron but one may surround plants of the allium family (e.g. onions, garlic and Luf).

(R. Yehuda): One may surround all species with mustard or saffron except for grains.

(R. Shimon): One may surround all species with them.

(Rabban Shimon ben Gamliel): Small rows of vegetables may be surrounded with them.

Baraisa: A person may plant a row of mustard or saffron in his field, as long as he makes a separation row 10 1/2 Amos long and a full row wide (i.e. 6 Tefachim).

(R. Elazar): This is only in a small field (meaning where the length of the mustard row is more than the length of the field, as it looks like the case of the 'Rosh Tur' - earlier in Halacha 5 - Menachos 38(a) that if the end of a row entered into barley, it's permitted as it's apparent that it's the end of his field); but not in a large field. What is large and what is small? If there is the space of a Beis Rova between the branches of mustard of this row and the adjacent row.

Question: This is against R. Yochanan who said there (Menachos 38(g)) that we don't apply the leniency of Rosh Tur unless it comes from a sown place that is the size of a Beis Rova in both directions, but here, it's like a Rosh Tur that comes from a sown area that is no longer in existence and it should be prohibited...?

Answer: There was discussing seeds; here is discussing vegetables - even though R. Yochanan disagreed over seeds, he agreed here over vegetables.

A dry area in a field may be sown with any species. (The produce that grows there is different to other produce, because it doesn't have a good supply of nutrients, so it looks like a separate field.)

(R. Yochanan): As long as three Tefachim are planted across the full width of the area. (Less than that does not look like a separate area.) The three Tefachim that are next to a fence are also like a dry area, so one may plant another species there.

If he planted three Tefachim of the dry area and one Tefach (of the same species) next to it, they are all saved.

If two Tefachim were inside the dry area and one Tefach outside, none are saved.

If there was a dry area and row next to a fence (which is also viewed like a dry area), with a row in between them, the two 'dry areas' surround the row and one cannot plant any chosen species next to that row. And if he wishes to plant one species on top of the fence and another next to the fence, he may do so as they are considered to be two fields.

Two adjacent fields with one higher than the other, if the upper one is close to a trench and the lower one is close to a fence, D'Bei R. Yannai said that he may plant there whatever he wishes.