Pond you re not a seed

You're a show, that comes on when I sleep
When I close my eyes
I'm just helping good things grow
Once a dog strayed inside my yard
Left in the wet dirt the impression of your paw
At least that's what I thought it was a dog
You were sown, watered when you were dry
You were just a seed
I was helping good things grow
Now you're gone, I know what you were
Not dream or seed or animal
You turned out to be a girl
At least that's what I think you were a girl
I don't have room for this big hole
It moves from wall to wall letting in cold
What more can something need to grow
Provided food and shelter and got back sorrow