Shabbos 8:3

One who reaps the volume of a dried fig is liable. Plucking fruit is a subordinate labor of reaping; one who removes vegetation from where it grows is liable for reaping. Therefore, one who removes grass growing from a rock, a parasitic plant that grows on a fern, or grass that grows on a barrel is liable because these are the places where these things grow. On the other hand, if a person removes something from a flower pot without a hole in the bottom, he is not liable because it is not considered the place where things typically grow. If the flower pot has a hole the size of a small root, then the plant is considered to be growing from the ground and one who picks from it is liable.

Shabbos 8:4

Some reaping causes a plant to grow larger, such as pasture grass and beets. One who harvests such a thing in a state of unawareness is liable for two sin offerings: one for reaping and one for planting (because he did something that encouraged plant growth). Similarly, if one prunes a tree intending to use the branches, he is liable for both reaping and planting. If a clod of dirt has grass growing from it and a person picked it up from the ground and put it on a post, he is liable for uprooting it. If it was on a post and he placed it on the ground, he is liable for planting it. If figs have dried on the tree - and the same is true of other fruits – one who picks them on Shabbos is liable. This is so even though such fruits are considered already detached when it comes to the laws of ritual purity.