Plant a perennial garden with plants that work in your geography. Cover shrubs in the winter to keep them from freezing.

Back Yard Shade Garden · More Info

Mid-Century Perennial Garden and Path - Racine · More Info

Ground cover, some bushes, large granite slabs and a water feature. A local nursery could provide advice.

What Sabrina said. Perennials along with some flowering shrubs would be nice. Any shrubs should be of dwarf varieties so they don't get out of hand nor require constant trimming. It looks like you may have to remove some soil - the grade appears to be higher than the walk by the gate. You don't want any soil or mulch washing on to the walk.

Since you said you want a low maintenance garden, I think Maureen is on the right track. I suggest a visit to the Denver Botanical Garden. You want to end up with plants that will survive in the lower water environment that you have in Colorado. Hydrangeas might not be the best choice.

I'd want a small tree, maybe two -- here in the South I'd say a Crepe Myrtle or Dogwood, but that may not be appropriate for you.

I really like that water feature shown above. I'd also like to see a small bird bath.

Since this plot is small but not so small you can't reach across it, I'd include some stepping stones to allow you to maintain the back portion.

And something to screen that HVAC.

www.stepables.com

Call a very decent tree and landscape venue locally, and let them make you a plan.

For me? That might include some hardscape and sitting area. Your pictures don't reflect the porch entry well. But the approach is essentially a tunnel effect I'd want altered. In other words? More than what you plant is involved for a really good look.

Yes to getting some local help BTW nothing uglier than covers over shrubs all winter . Go evergreen for shrubs for sure . I love periwinckle for ground cover some bulbs planted in the ground cover for nice splash of color in the spring and some smaller type perennials that do not require a ton of upkeep.and can withstand the climate

Look into PlantSelect.org. They've tested a variety of perennials, shrubs, and trees that do well on the Front Range (you'll find the plants at various nurseries around town). Garden in a Box is a great way to get a pre-planned garden. You can buy kits in the spring with all the plants you need or just download their plans and buy the plants on your own. https://resourcecentral.org/gardens/

It's too late in the season to plant now so start working on what you want for next year. Ideal planting time is April-May before it gets hot, then again in September.

BTW, we don't cover shrubs here; look for zone 5 plants. You can try some more sensitive plants (rhodies) but you'll need just the right environment and some luck to succeed. Test your soil first to see what nutrients are needed and just how alkaline the soil is. Colorado State University has an extension service that provides lots of info about growing in Colorado; https://extension.colostate.edu/topic-areas/yard-garden/

Looks like the spot is mostly shady being between a building and tree. So you need to look at shade tolerant plants. I don't see how a water feature is low maintenance, since you have to deal with plumbing issues. But, maybe it's possible. Find some small plants for your zone that can deal with shade that you think look good. Small plants are generally less maintenance than large plants. You can easily dig them up if you don't like them.