1. If It Is Permissible to Walk on Grass or Climb a Tree, 13 Seifim: We do not climb a tree, whether it is wet or dry, nor do we hang from it, nor do we use anything attached to the ground. This is a rabbinic decree lest one come to climb the tree and pick something from it. If someone climbed a tree on Shabbat by mistake, he is permitted to descend. If he did it on purpose, he is not allowed to descend. If he climbed the tree when it was still day on Friday, he is always allowed to descend after it gets dark. There are some who say that this only applies when it was his intention to descend while it was still day, but if it was not his intention to descend while it was still day, he should not descend when it gets dark, as he intended to sit in a forbidden place. Rem"a: This only applies to a person who ascended the tree, but if he left an object there while it is still day, it is forbidden for him to remove it from there on Shabbat (Magaid Chapter 21). All of this applies to a tree or the like, but one is permitted to use reeds that are soft like an herb, even if they are connected to the ground, because there is no prohibition against using herbs (Hagahot Oshr"i Perk Bechol Me'arvin in the name of the Or Zarua and Beit Yosef).
2. If a tree's roots are three tefachim above the ground, it is forbidden to use them. If they are less than that height, one is permitted to use them, because they are considered as if they were ground. If they slope downwards, they are forbidden where they are taller than three and permitted where they are shorter than three. If they are three [tefachim] tall with empty space below them, even though on one side of them there isn't empty space and they are level with the ground, it is forbidden to sit even on the side that is level with the ground.
3. One is permitted to walk on grass, whether it is dry or wet, because he does not intend to uproot it. However, those who eat in the garden are forbidden to wash their hands over the garden, because they water the plants. Even though this is not their intention, it is an unavoidable consequence ("psik reisha") of their action. However, it is permitted to urinate on them or to dispense other liquids that do not make the plants grow. Rem"a: Therefore, it is a good idea to be stringent and to not eat in a garden if one is using water, because it is difficult to be careful not to spill some water there (Beit Yosef in the name of Sefer HaTrumah).
4. One should be careful to not throw seeds in a place where it rains, as they will eventually grow. If one throws seeds to chickens, he should only through the amount that they will eat in one or two days. If he is in a place where people walk a lot, it is permitted, because the seeds will not grow.
5. Vegetation that grows on the spout of the pitcher from the moistness of the pitcher is considered as if it were attached to the ground, and he who picks it off is liable.
6. If vegetation is inserted into dirt while it is still day on Friday so that it will be wet, it is permitted to grab the leaves and pull it out, as long as it has not taken root. It also must be the case that he didn't want it to take root. However, if he intended to plant it, this is forbidden.
7. It's forbidden to uproot plants even from a flowerpot that is not perforated.
8. With a flowerpot (meaning a half jar in which vegetation is planted (The Arukh)), even one that is not perforated, one must be careful to not carry it from the ground to pegs or the opposite, whether it is wooden or clay. Rem"a: If a tree branch fell from a tree on Friday and it has fruit, it is permitted to pick the fruit from it on Shabbat (Rabbeinu Yerucham Path 12 Part 2).
9. If a pipe on the roof that emits water becomes filled with straw and plants that block it and stop its flow and the water is spreading around the roof and leaking into the house, it is permissible to crush the plants with your foot quietly. Because he is fixing it slightly differently, just using his feet, in the case of loss, the rabbis did not decree against this.
10. It is permissible to smell myrtle that is in the ground, but it is forbidden to smell a citron or an apple or any other edible thing when it is connected to the tree/ground, lest one be tempted to eat it.
11. Soaking wheat or barley or similar things in water is a subset of the prohibited labor of planting, and one who does this is liable for any quantity. Rem"a: One is permitted to put tree branches in water on Shabbat as long as they have no flowers on them, because flowers develop in the water (Mahari"l), and see below Chapter 654.
12. If there are figs that have dried out on the tree or other fruit that have dried out on the tree, one who picks them on Shabbat is liable even though they are treated as if they are uprooted for matters of impurity.
13. It is forbidden to use the sides of a tree, but it is permitted to use the sides of things on the sides of a tree. Therefore, it is forbidden to lean a ladder on a tree, because if the ladder moves, you'll be using the sides of the tree. However, if there is a peg stuck in the side of the tree, it is permitted to lean a ladder on it, because the peg is on the side of the tree, but the ladder is on the side of something on the side of the tree. If one sticks a peg in and hangs a basket on the peg, the peg is on the side of the tree and the basket is on the side of something on the side of the tree. Rem"a: One is permitted to touch a tree as long as he does not shake it (Beit Yosef in the name of Orchot Chaim). It is permitted to descend and ascend a pit of even 100 amot, climbing down and climbing up. We do not worry that he will uproot land while ascending and descending (Tur).