I have similar conditions, just a lot warmer in the summer! I don't have any suggestions, other than to ask your county's cooperative extension. They know what plants work best for your conditions. I know I've received invaluable help from mine. I bet though, you could grow ornamental grasses successfully. We have to be careful which ones we grow down here because they can get invasive. Barb

If you're doing a cover crop then part of the sequence is to actually cut the crop before it comes to flower so you get plenty of juicy material that rots down quickly - and has enough fibre to not make a felted mess (like you see with heaps of grass clippings.) The roots stay in the soil and, as they rot down, add even more humus to the soil. It is really important to not bury the cover crop deeply, It can combine with clay to make a bit of a toxic brew for a while. If you live in a rural area observe how the farmers disc in the crop residue (hoping that they don't burn off.) You might also notice that some farmers turn stock onto the crop residue to clean up and add manure before they disc. You'll need to have an acceptable process to add extra nitrogen to the soil as the cover crop rots down. Something slow acting, such as blood and bone could be useful, although it can attract animals. Perhaps dried animal manure would be an alternative. Your biggest hassle would come if you have a perennial weed (like dandelions, dock, twitch grass, or whatever your local nightmare/s happen to be) growing in your cover crop. The darned things LOVE being disced. It spreads little bits of root everywhere - and, being weeds, they usually all grow. A cover crop can be highly useful in a poor soil - and to give protection if wind or heavy rain moves soil in your area. You might also want to consider growing a cleaning crop such as potatoes, or rows of peas that need regular weed control and/or hilling up. If you were to lay down a mulch between the rows, along the lines that lindac has suggested, then you could have 'the best of both worlds'. If you do decide on doing the cover crop - and leaving it over winter (a ryegrass, mustard, lupin, barley, clover, vetch crop would probably all be suitable) remember to leave enough time between the cutting back, digging in - and your planned planting date - for the material to rot down, or plant crops that will tolerate quantities of partially rotted material in the soil. Also think about any fertiliser/liming that needs to be done, too. Those additions need time to become effective in the soil for following crops - and some crops don't like them too fresh.

brigite22 No photo possible? Are the large rocks attractively arranged? If not, hiring some one with a large crowbar or a Bobcat to shift some of them might help. Here are a couple of photos showing a sloped part of Thyme2dig's (one of this forum's members) garden. The large boulders were a byproduct of construction and/or road building and are placed in an attractive and functional way to help hold the slope as well as looking tidy and natural. She has a few plants in front of the rocks and some spill over from above to soften the rocks and make them look a part of the garden. These beds get a good amount of sun, so the specific plants might not work, but it gives you a good idea of how beautiful a hill (or mound) can be. This one has rock steps going up to the top, while the front has brick and wood steps. You might want to consider adding a path or steps up onto your mound with a path or stepping stones on top to help it look like a deliberate garden rather than leftover rock and soil. I like the way T2D uses a mix of shrubs and perennials, densely planted and mulched to help reduce weeds, to keep the area beautiful year-round. With a bit of planning and some care, this area can most likely look like a planned garden, not a leftover heap. I would start with planning whatever hardscape you want to add like steps, paths, garden art, etc. If you add paths, I'd put in edging to keep the groundcovers out of the pathways, but with stepping stones, just be sure to plant low growing plants in the walking areas. Leave the accumulated leaves there (though you can move them off your rocks), but pull any weeds and do any hardscaping. Over the leaves, put down a layer of corrugated cardboard or a thick layer of newspaper (wet it as you go to keep it in place) and then a good layer of hardwood mulch, again leaving the rocks exposed. This type of mulching is key to making the area low maintenance as it will keep down weeds and hold in moisture in a way that groundcovers alone won't. You will probably need to spend a couple of hours late spring and fall weeding, but not more than that. 15 minutes a day for two weeks a year is doable for most folks. Every few years you will need to add mulch until the ground cover has completely filled in. Consider adding plants with a variety of heights, leaf size, color and texture. Low maintenance, lower shrubs that are fine in somewhat dry afternoon shade: Microbiota decussata (AKA Russian arborvitae) evergreen Any of the smaller Hydrangea paniculata varieties such as 'Little Quickfire', 'Little Lime', etc. (none of the other Hydrangeas are tolerant of dryness, but H. paniculatas are.) Low bush blueberry (Vaccinium angustifolium) smaller rhododendrons such as the various R. yakushimanum such as 'Ken Janik', 'Yaku Prince', 'Yaku Princess', etc but you may need to water if it is really dry for really long Diervilla (bush honeysuckle) Perennials that would work with your light: Anemone sylvestris - spreads Partridge berry- (Mitchella repens) very low some of the smaller gold-leafed hostas which tend to be more sun tolerant Heuchera (coral bells) and Tiarella (foamy bells) and Heucherella (a cross between the two previous) Japanese forest grass (Hakonechloa macra) ‘Aureola’ gold foliage Carex 'Ice Dance' or C. 'Banana Boat' (along with many other Carex which often like part sun and tolerate dryness) - spreads Lamium maculatum (deadnettle) - spreads Ground cover Epimediums- spreads smaller daylilies like 'Happy Returns' Hellbores will spread via seed, but not aggressively Smilacina racemosa (false Solomon's seal) may be listed as Maianthemum racemosum - will spread via seed, but not aggressively Assarum spp (wild ginger, but not the edible kind) slowly spreading Polygonatum spp. (Solomon's seal) will slowly expand clumps Iris cristata (crested iris) will slowly expand clumps and is only about 6" high with light blue or white spring flowers. Some of the hardier Alstroemeria such as 'Sweet Laura' Geranium Bevan's Variety or G. macrorrhizum or G. biokovo Campanula poscharskyana Pulmonaria (lungwort) will spread via seed, but not aggressively Phlox divericata - (woodland phlox) Dicentra eximia - (fern-leaf bleeding heart) Pachysandra (kind of boring, but would be OK as part of a mix) - spreads You might want to put in some smaller daffodils and species tulips in the sunniest spots for early flowers.

Kinnikinnick, Arctostaphylos uva-ursi. This plant is native to much of the country, evergreen, very cold hardy (z2) and pretty drought tolerant once established. it is also not the slightest bit picky about soils except that they be well draining. Does not spread all that rapidly so be prepared to bit a patient for full coverage or decrease the spacing. I would also consider mulching after planting to retard weed development, preserve soil moisture and add nutrients back to the existing soil.