Ask Mr. Smarty Plants

In selecting plants for an area, the exposure (east, north, etc.) is not really as important as the amount of sun the area gets in a day. We regard full sun as 6 or more hours of sun a day, part shade as 2 to 6 hours of sun and shade as less than 2 hours. Pembroke, Plymouth County, is apparently in USDA Hardiness Zones 6a to 6b, with average annual minimum temperatures of -10 to zero deg. F. Obviously, with shorter days and as far north as you are, even the morning sun is going to be less for a while, but you might make a rough sketch of your property with indications of the amount of sunlight  various areas receive.

We are going to go to our Recommended Species section, click on Massachusetts on the map, and then select some herbaceous flowering plants (herbs), shrubs, and grasses, checking each one to make sure it is native to your area of the state. We'll try also to find evergreen low-growing groundcovers. You can repeat this process, putting in the appropriate amount of light, soil moisture and so forth in your searches. We are just going to give you a sample and you can go from there. Incidentally, on a slope, there is no better plant to use than grasses, with their long fibrous roots to hold the soil. These are not going to be mowed lawn type grasses,  but taller, more ornamental grasses. Follow each link to the page on that individual plant to learn projected size, light needs, soil moisture, growth habit, bloom time, etc. We are going to search on "Part Shade" and "Shade" as we feel that's about the best you could hope for in your situation.

Plants for an east-facing slope in Plymouth County, MA:

Gaultheria procumbens (eastern teaberry) - low, woody groundcover, evergreen, blooms white, pink June to August, part shade or shade

Arctostaphylos uva-ursi (kinnikinnick) - trailing evergreen shrub for groundcover, blooms white, pink March to June, sun, part shade or shade

Coreopsis lanceolata (lanceleaf tickseed) - perennial, evergreen, blooms yellow April to June, sun, part shade or shade

Mitchella repens (partridgeberry) - perennial trailing herb, evergreen groundcover, blooms white, pink or purple May to October

Lobelia siphilitica (great blue lobelia) - perennial, deciduous, blooms blue July to October, sun, part shade or shade

Rhododendron maximum (great laurel) - evergreen shrub, 4 to 15 ft., blooms white, pink in June, part shade

Cornus alternifolia (alternateleaf dogwood) - deciduous shrub or small tree, 20 to 30 ft. tall, blooms white May and June, part shade or shade

Calamagrostis canadensis (bluejoint) - perennial grass 3 to 5 ft. tall, medium water use, sun, part shade or shade

Muhlenbergia schreberi (nimblewill) - perennial grass, part shade or shade

From our Native Plant Image Gallery:

Gaultheria procumbens

Arctostaphylos uva-ursi

Coreopsis lanceolata

Mitchella repens

Lobelia siphilitica

Rhododendron maximum

Cornus alternifolia

Calamagrostis canadensis

Muhlenbergia schreberi