Last spring, I bought an apricot tree and planted it in my yard. I put cedar mulch around it, as well as one of those plastic things to protect from animals eating the bark. It is still alive and it grew leaves in the spring/summer. However, it doesn't seem to be growing at all. It is planted in full sun, but it gets a little shade later in the afternoon, say around 4pm. The soil is pretty hard with a lot of clay.

What do I need to do to get this tree growing?

Thanks in advance for your help.