I attempted to do that in the far corner of my backyard by sectioning it off from the rest of the yard with a boxwood hedge and a simple iron arbor. There was an existing mature apple tree that gave me a good start on the feeling of being closed in. I added several Japanese maples and a chair and after just a couple years it really is starting to feel like a cove.
|Japanese maples - Seiryu (in the foreground) and Iniba Shidare in the background|
My satisfaction peaked the other day when my daughter came out to read while I worked in the yard. I wasn't paying much attention while I worked but when I looked up and saw that she had chosen to sit in this uncomfortable chair and read a book I was thrilled. Thrilled that she loves to read so much and thrilled that something in her was drawn to spend time in this part of the yard.
I could stand to learn a few things from her example.
After she caught me taking this picture she started hamming it up for the camera. Here's a better view of the way the "cove" is coming together: