Throwing seeds and pits onto the ground:
One is to beware from throwing seeds in an area where it rains [or in an area that the earth is wet] and can eventually cause the seed to grow. It is however permitted to throw them in an area that the seeds will certainly be destroyed prior to any chance of growth, such as in an area that people walk. Likewise one who owns chickens may throw them the amount of seeds that they will need for the next two days, as certainly these seeds will be eaten prior to any chance of growth.
 Seemingly this includes all times, including the summer, in those areas which don’t have rain in the summer, as perhaps the seed will last until the rain season and then be able to grow. In any event since it is not inevitable that the rain will come at a time that will allow the seed to grow, and it is hence not a pure prohibition to throw the seeds in such areas, but a mere hazard. [based on Ketzos Hashulchan 142 footnote 19]
 Based on explanation of M”B/Chayeh Adam in definition of “place of rain”.
 As certainly in such an area the seeds will not grow and hence there contains no prohibition of planting. [ibid]