In order to make the foreground plant stand out a bit I outlined in white. There is still a bit of a mess in the middle between that plant and the right hand one by the door. That is going to need some more attention. I also noticed that the pot on the left hand one is a bit too big and is taking over too much of the balcony there.
I then extended the left hand door a bit out past the end of the wall. Layered shapes shopuld never end on the same line but always overlap partly and protrude. It make for more interesting composition. I then tone down the sky a bit so that you can see the door better.
I was still not happy with the low walls. The near one needed a bit of straightening, which I did (if you can notice it). The far wall got slightly more radical treatment which you will see in my next post.