you might want to try this on the pest and disease forum .. or take a piece to you local Ag agent ... ken

I would also suggest the eleutherococcus. I have two, one closer to the silver maple (and under the canopy all day). Of the two, the one that is farther away is a bit taller, but both are holding their own and the bright leaves look nice in the deep shade. During last summer's really dry spell, I watered the one closest to the tree several times. This year, we've had so much rain that, even now, in mid-June, the soil in the maple's root zone remains damp. The shrubs I have now were planted as sticks in the summer of 2006 and are about 3' high. With more sun and more reliable water, they would grow a good bit faster. The one in my z5 garden was 5' tall by the end of its third growing season and was filling out well.

I've got Winter Jasmine, the flowers took a hit this winter as it went down to -4F one night when it was in full bloom in December. I've had this shrub for over thirty years, actually it was my neighbors, she planted it on a trellis on the side of her carport but I took it over when she passed and the house was sold. This is when we found out her concrete carport encroached our lot by 8 inches so I laid claim to it, the Jasmine that is :o). Back to the Jasmine, this one isn't scented but depending on the winter it can bloom anywhere from November through March here on Vancouver Island. Every spring before it leafs out we take the hedge trimmer to it cutting it back severely (to stubs), the new growth cascades down like a green waterfall from the the top of the carport all summer long. The flowers come after the leaves have fallen, it seems to be in full bloom at a different time each year, even now after getting hit by our unusually cold winter it's still producing a few flowers. Annette

If you are considering Prunus, then I'd focus my attention on a native species, Prunus caroliniana, Carolina cherry laurel. This can grow to a considerable size (much more tree-like than shrubby) but dwarf cultivars are available. I'd also consider Japanese aucuba, Aucuba japonica. Will grow in almost complete shade, very drought tolerant once established and grows rapidly. Other choices would be some of the hollies - Ilex opaca, glabra or crenata - all quite shade tolerant but slow growers. Also Leucothoe fontanesiana (also a native), Pieris japonica, Viburnum davidii, Eleaegnus pungens or one of the taller Sarcococca species. Nandina domestica and mahonia are also possibilities but both have invasive tendencies in your neck of the woods. My second suggestion is to consider a mix of suitable evergreen shrubs. A single species planting invites more disease and pest issues than does a diversified planting and diversification encourages wildlife and offers more visual interest. Wouldn't hurt to throw a few deciduous shade shrubs into the mix also - they will help with the screening (at least during the growing season) and typically offer showier flowering and often fall color as well. And there are LOTS to choose from - Itea, Clethra, Fothergilla, Disanthus, Callicarpa, Kerria, shrub dogwoods, more viburnums, hydrangeas.....etc., etc. btw, plants really do not help with muffling road noise - you need either a significant distance or a solid surface (solid wall or fence) to really accomplish that feat.