Welcome to the Forum!

Considering you have to watch where you dig, around that problem, you can use Carolina Jasmine, or Crossvine, as a vine, on the trellis.

I think you need to stay with a trellis, as you will actually be limited on what you can put there, by the utilities. They can actually tear anything that hinders them, out of their way, without your permission.

Carolina Jasmine can be acquired already on a trellis, but in this use, I would say that you should put in your own, and side-plant the vines, then allow them to grow across the trellis, to minimize conflicts with the utilities.

Carolina Jessamine stays green and has lovely yellow blooms that smell good and the bees like.

Crossvine and Coral Honeysuckle(both natives) are evergreen but I'd stick with something smaller like a Carolina too. These might get too gung-ho for a small,controlled area. They are not aggressive like Jap Honeysuckle or Trumpet vine tho.PJ

I hate to disagree with some the sage regulars on the forum, but Carolina Jessamine just about swallowed whole my fence, in about 3 years. I was constantly having to thin it because it was overgrowing everything - and that is in my DFW yard where it is semi-evergreen. In your zone 9, you might wish for something not quite so agressive. Most of the folks in my neighborhood that have those lovely accoutrements in their yards plant shrubs around them and then hope the utility company never has to chop down the shrubs (but I have seen some that have been). Whatever you decide, good luck with it.

Welcome Lynda
You could still put a lattice or whatever trellis and hang a planter or have a potted plant in front or around
something like the link below
jolana

Here is a link that might be useful: lattice trellis

We have electric boxes too, same problem. Up to this year we have planted a wall of cannas to block their view. We don't want to do that anymore. I have searched off-and-on for something I saw on TV. Faux rocks. Realistic looking plastic things, hollow on the inside and big enough to simply cover the boxes. Easy to just peel off if the boxes need to be accessed. Then for plantings, some kind of arrangement of potted plants to go with the "rocks."

I have almost gotten the gumption to try my own hand at molding & finishing homemade faux rocks. Almost...

I can't give any gardening tips, being a newbie myself, but I can elaborate on the limits of your rights and the utility company's rights as far as the utility feature is concerned.

Generally speaking, utility companies here in Texas place the transformer boxes in the center of a 10' x 10' utility easement. If it's in the back corner of your yard, measure 10' from each fence and that will show you the limits of the easement (assuming it's a typical 100 sq. ft. easement). As another poster mentioned, the utility has the right to access their equipment at any time and to remove any obstruction that would prevent access to their equipment. So, don't put anything in that area that's permanent, like a greenhouse or some other substantial structure, since it could cause a safety hazard in the event of having to remove the equipment in an emergency.

I can speak to Crossvine though - this is the beginning of my second year with mine and it's looking good so far. I can't thank this forum enough for providing the background on it and steering me away from some other more invasive species.

How about a grouping with a mixture of native ornamental grasses. Vary the height and texture and plant a bit away from the box.

Big (Lindheimer) muhly grows to four feet and sends up lovely plums, Maiden grass also tall, Gulf muhly lower (2 1/2-3') with gorgeous purple plums in the fall, Mexican wire grass (2') with a soft texture that blows in the wind.

These are easy to take care of and much less work than setting up a trellis and worrying about intruding on the utility's right of way.

Check the link below for pictures and information. Go to pages 11 & 12.

Best of luck & Happy Gardening

Here is a link that might be useful: Austin Grow Green