Chapter 26
Plants and Trees
18.a. The prohibitions against the use of a tree, and of it directly hanging from, attached to, or supported by tree, are applicable even where the performance of a mitzva is involved.
18.b. It is, thus, forbidden to take a book off a tree, or off an item which is directly hanging from, attached to,or supported by a tree, even if one wants to use it to study Torah and has no other book of the same nature.
19.a. One is allowed to walk on a lawn on Shabbath or Yom Tov, regardless of the possibility that one may thereby pull up or tear off clumps or blades of grass.
19.b. Nevertheless, any pieces of grass or vegetation which one does find stuck to one’s shoes should not be removed in the normal way with one’s hand, since they are muktzeh,
19.c. If the grass is long, one should walk slowly and should certainly not run, as one would be bound to pull up or tear off some of the grass in this way.
19.d. One should not tread on dry thistles which are still attached to the ground, because they will definitely break off.
