To dream of a backyard represents issues or situations that you don't like thinking about. Something you don't like noticing or seeing in yourself. Things you don't want to confront, don't want to deal with, or make you upset when you have to think about them.
Backyards in dreams may also reflect issues you want to keep hidden from people or jealousy of having to deal with an embarrassing issue. Irritation or prolonged trouble.
Example: A man dreamed of standing in his backyard. In waking life he was embarrassed to be witnessed by other people as single person with no girlfriend or wife.