Describe your climate. It can help to name the largest nearby city. Add photos showing what is toward the right and left of this photo -- taken from the same vantage point. What is behind this point of view? Street? Fence? Context is helpful.

In other words what is your geographical location? And what attributes do you want these shrubs and perennials to have? Size, shape, color, fragrance etc.

This uses Bergenia, Sumac, Dwarf Yew, Miscanthus, Knockout Roses & Silverberry Eleagnus.

I’m in zone 6. I need low maintenance shrubs that don’t require pruning. I’ll fill in with perennials gradually. The photo shows half of the slope. I love Doug’s photo - thanks for naming the plants. I’m familiar with KO roses but that’s it. We have a lawn in front of this slope. The house is on a hill and as you drive up the driveway, you see this slope from a distance. I’m thinking I should plant shrubs in groups.

Zone 6 WHERE!?!?!?! It matters. For example, I wouldn't plant sumac in a civilized planting anywhere near here. It will sucker and make a mess.

Some strategic color in the planter, an array of small flowering trees on the slope with groundcover below. No mass shrubs in lieu of groundcover.

Pennsylvania near Harrisburg

Check out the work of Oehme & Van Sweden before dismissing Sumacs & other native ornamentals. As for low ground cover, they often become weedy messes on slopes.

Doug, I grow staghorn sumac, and love it, but I would never plant it in a suburban yard. The two clumps I am most familiar with require regular mowing nearby (not easy on a slope) to keep them in check, and both clumps are very large, 30-50' across. Your drawing of a single plant takes a lot of maintenance to restrict in real life IME.

In much of the northeast, Elaeagnus is invasive, seeding both near and far courtesy of the birds, so I would check with your local state dept of natural resources as to its status near you. A couple species are referred to as silverberry Elaeagnus, so I can't be sure which Doug is referring to.

I have a steep slope across the back of my house that I planted with a pair of thuggish suckering perennials (orange ditch lilies/Hemerocallis fulva and Centaurea dealbata) and mulched heavily with tree chippings to hold the soil. Over time I have planted a range of resiliant shrubs after pulling back the groundcovers in the vicinity, including a Burkwood Viburnum, a rugosa rose hybrid, a couple of hydrangeas (H. paniculata seems quite happy) and a couple of smaller dogwood trees. I kept replenishing the mulch until the groundcovers filled in, and usually weed twice a year, in early spring and about now near the time of the first frost. If you want minimal maintenance, a dense groundcover, initially paired with mulch, is essential.

Probably planting the shrubs and groundcovers together would be better, but my planting was dictated by the construction schedule since I didn't want the shrubs damaged before the reroofing and residing was finished, but I needed plants to hold the soil, so if at all possible, I would plant them at the same time and then immediately mulch well. Otherwise serious weeds will grow.

I like MadGallica's suggestion of evergreens of some type to give winter color and interest, but I don't think that all of the plants need to be evergreen.

There are many ways to create a terrific hillside planting. What you prefer depends on your sense of style. As for planting choices, there are at least 10 good substitutes for any plant used in a design.

Sumac was just one of a number of possibilities. I did not specify a particular cultivar of sumac because this is just an idea forum. However, when I draw designs which include specifics for clients, I would specify dwarf staghorn sumac which grows to about 6-8 ft & forms small clusters. As for the type of Eleagnus I am referring to, it is a more southern species not suited for PA.

If you study some of the work of Wolfgang Oehme & James Van Sweden, you can get an idea of how these plants have been used.

One caution I have regarding hillside plants is to not use very low cover unless you are able to keep the weeds out.

"Fill in with perennials" = significant additional work. And I wouldn't fill in with anything, I would have interlocking drifts of each kind. Chosen specifically and with purpose for how they look against each other.

Just a word on low cover groundcovers that are highly weed suppressing, whether they're on a slope or on a flat area--Geranium macrorrhizum, G. 'Biokovo' and 'Karmina', Persicaria affine and P. amplexicaulis cultivars.

Nancy, the former junipers you removed probably were slowly killed by field mice that burrow under them for winter protection and chew off root bark. Very common problem in snow country. Keep this in mind as you plan. Some random thoughts. You live in rock/boulder/fossil country. Any chance the budget would allow placement of large rocks set into the hill? Think about your design starting at the street looking toward the slope. Where should the approaching 'focal point' be in your design? Doug has illustrated a good idea, a spot he thinks an open type small tree belongs, such as a Dogwood, maybe? But then, there would be leaves to rake.

To create a maintenance free garden on this slope is difficult. And climbing, working on a slope, trying not to stand on growing clumps of plants is difficult. But, a rock garden approach should be added to your considerations. This allows areas of mulched blank spaces to appear natural with careful planning. And, rocks never need maintenance and weeding.

Nandina has a good idea there--alpine/rock garden. Sempervivums and Sedums and the like, with some dainty dwarf conifers.

Successful use of low ground-covers depends on the bed being completely clean before planting. And there not being any kinds of plants present on the site that will seed into the low height carpet later, have to be extracted. In my area long-established plantings of tamarix juniper aren't even deep and thick enough to fully exclude blackberries, alders etc. During a college level class I took one time it was stated ground covering plants really had to a minimum depth of 2 ft. for it to be possible to realize the goal of them eliminating weeding.

I garden on gravely slopes and I have had good luck with creeping junipers, including but not limited to the ubiquitous "blue rug juniper." Also smaller pines like mugo pine, (dwarf variety) and if you don't have deer, there are some low growing arborvitae and cryptomeria. As for perennials, there is native mint called "mountain mint" that I have grown from seed and had good luck with. Also yarrow, lamb's ears, thyme and sedums have grown well and held their own against erosion. Also ninebark and some of the viburnums have done well. Rugosa roses have had mixed results. Another great low growing shrub is magic carpet spirea and some of the other low growing varieties like goldmound. I just planted a dwarf aronia (common name chokeberry) and I can't say how well they will do overall but they are gorgeous. Catmint and russian sage also do well. Oddly, milkweed also thrives. Just some ideas. I would not put a hodge podge of things there as some have pointed out, does not look good and is difficult to maintain. Plan for drifts. Also, to prevent erosion, you want plants that will continue to hug the ground as they grow, not just when they are young. We had some junipers that looked great when young but now that they have grown up, they just don't hug the ground enough to suppress weeds or hold back as much water as they did when they were young. Mind you these plants are 80 years old now, but still the principle is there.

Another option are some of the ornamental grasses. So far I haven't had much luck or experience with the native ones, but I sure have seen some beautiful landscapes featuring them. However, that is a look I think that is difficult for the average home owner to achieve, mixing grasses with other shrubs and plants. That's a project I am working on now, just planted it yesterday and we'll see how it goes . . .

Thanks for the Oehme & Van Sweden inspiration, DDD.

Continuing the "sumac" discussion, here is a photo of creeping sumac and a grass background. That would look great on your slope. The scientific name of the plant I am talking about is Rhus trilobata. It looks nothing like the staghorn sumac you see by the side of the road, other than it has great fall color.

**Update. July 2019
After lots of research and reading many advice posts, I have covered my slope. Still a work in progress (what garden is ever finished??) but I’m happy with this start.

That's lovely! I like the way the plants are similar heights, but different colors and textures. It keeps it looking cohesive even though there's lots of variety.

Beautiful! What are the golden plants in the second pic?

You probably are looking at the Angelina Stonecrop Sedum. Now on its third year, it isn’t as tight and I have weeds growing between. Something to think about if you’re looking for a good groundcover. It does look pretty!