Hi Deo,
Imagine you have a house facing East and only flat land behind your home. In this case, a high hedge behind your home (which is in this case West) is a very good idea to cover your back. I would not be so strict about the corners. If your plants need more sun and you only have a balcony or a window in the Southwest, please place your plants there. I wouldn't be so strict about the general sectors, they are the basis but there is more to feng shui than that. In Time Feng Shui, there are situations when you need plants in the southwest, west or northwest (or any other sector) to balance the energies. Please relax and put your plants on your balcony and enjoy them
Have fun,
Astrid
