I must confess, I have never seen those located in the middle of someone's property. They are usually found at the junction of adjacent properties.

You don't want to plant anything that will impede access to the towers, or it will be damaged or destroyed the first time someone needs to access them.

Most people plant some type of tall grasses around them, which can permit easy access, with minimal damage.

Since they are located in a highly visible location, you may want to add some additional plantings around the grasses or other tall plants you choose, to provide a more pleasing appearance.

Before digging near the towers, I would call the Utility Locator service number, usually found in the front pages of the phone book and have them mark the exact location of the cables. Installers don't always follow conventional and logical rules when they place those cables!
If you damage the cables, without having them located, you could be charged for repairs.
Rb

Ditto on calling the utilities. If nothing else, it's very good information to have. I sliced a cable line that was only about 2" max underground and way out in left field from where it "should" be. Thankfully it was not connected. A man from the phone co. told me there is 220v running through a phone line when it rings - I find that a bit hard to believe, but it is what he said and I'll respect that.

call before you dig is a one stop source to get all your utility lines marked. Within three days after asking for this service, all my utilities had stopped by and marked my line paths.

I've seen people put short cedar fences around boxes placed in a yard, and plant shrubs on the outside of the fence. That way none of the plants get ruined and you can really use anything you want so long as there is access to the inside of the fence and boxes. They have a lot of those in-the-yard boxes going on in Fla.

A neighbor had one of those big boxes in his front yard and planted pampass grass around it. A couple of years later, he was told to remove it because it limited access to the box. So I'd call first.