If you live in a tall block of flats, you many not have a garden. But there is much you can do with a balcony and even a windowbox.
In this case you can focus on attracting birds and insects such as butterflies and ladybirds. Notice you can use plants that trail (hang down) as well as plants that grow up.
It is amazing how you can make a balcony into a mini-forest with just a few pots around the edge.
