Thank you for answer. How may I treat an infested potted plant on a tiled porch, 4th floor? Also, may I remove dead leaves on plants that are sprouting new leaves? What may I do with completely dead plants? Indoor and outdoor. Thank you

ב"ה Shalom, If the porch does not have a roof above, regardless of the 4th floor, then it is considered outside. On the other hand, if there is a porch above your porch and there is a wall around the flower pot at least 80 cm high, then your flower pot is again considered inside and you may do any necessary treatment. Furthermore, if you wish to take the pot indoors, you may do so and then treat the plant without Shemitta restrictions. However, in such a case you MAY NOT take it out again to an outdoor environment with no rooftop. In outdoor conditions, you may treat the sick plant by spraying it or cleaning since this an action of maintaining the plant and saving but not promoting growth. Also, the pruning of dead leaves may be done, but it should done in a way in which it is not promoting new growth. In regard to the removal of the dead plant the best is to cut the dead part of the plant above the ground. All the best