Ground-cover planting will have to be kept weeded during establishment - and in the case of low covers like those you listed forever after also, as taller plants will be seeding into it and popping up in perpetuity. Things like red alder, various brambles and so on are very apt to insinuate themselves into even quite dense carpets - unless these are at least 2' thick. Even then you will always get at least a few intruders here and there, that you have to wade in and remove. Something like salal might be your best best but with that (and any other cover tall and thick enough to dominate) you will be talking about substantial root growth, maybe with a Heath Family plant like it not so deep but definitely forming a thick, woody mat, that would have to be cut away to access the utilities, should that ever be required.

It's kind of a big area but maybe covering it with cobbles is the best solution.

Yes, I get that rogue plants may disperse themselves, that's with anything that may get planted. We talked to a "landscaper" today, who does mainly lawns, and his suggestions are, ceanothus, kinnikinnick, lithodora and vinca. Not sure if I'm hep to the cobbles.

Warning about the vinca! Can be very invasive. How much maintenance do you want to have? The pines look healthy and I would add some interesting conifers, various heights, with some mounding evergreens and mulch between. I agree that the cobbles are not very interesting and the effect will be to just look like a very wide driveway.

You want something invasive here. The only trimming needed would be where the walkway and driveway are.

I would think a combo of vinca and hypericum would work as well as anything for the price. Surprisingly, they grow together quite well. The hypericum shades the vinca. Together, they form an almost impenetrable groundcover.

Spray the lawn with glysophate when it turns green, put down plops of topsoil and plant the plugs in the topsoil. Then apply a thick mulch. It would work just fine this time of year. No digging or removing the lawn!

Mike...been there, done that.

Vinca and hypericum, eh? Interesting combo. This is the place that's for sale, so I'm not eager to put too much attention into it. Let the new owners decide but my partner wants to dress it up a bit and solicited ideas. It's time for me to seriously disengage my attachment, not an easy thing to do. Thanks Mike. Always open for ideas.

Yep.