Dark Knight Caryopteris, Neon Flash Spirea, Canyon Creek Abelia, Var Red twig Dogwood, Dwarf Butterfly Bush...

Have a look at the Viburnums.

Here is a photographic list of full sun, Zone 7 shrubs. http://bit.ly/FullSunZone7Shrubs22 Pick out the shrubs you like. Click on this link for an ebook with landscaping tips that will help you get a more professional looking results. http://bit.ly/LandscapeEbook22 Good luck.

Second luis_pr on the paniculatas. Note that the black walnuts are challenging for hydrangeas and some other plants…need to be planted at least 20 feet away supposedly because of the juglone from the trees. You should be able to get a list of shrubs that are particularly affected by juglone online.

If your landscape doesn't already include white reblooming azaleas (most DC area homes are awash in azaleas LOL) they are a possibility.

Also, thousand canker disease (TCD) is killing black walnuts in northern Virginia. As a walnut owner, you should be aware of its' symptoms.

FWIW Hydrangea macrophyllas are perfectly fine in the DC area if they have enough shade, although, of course, they won't be as long blooming as they would be a climate with cool summers like Cape Cod or the UK. (true of most plants!) In fact I would say that generally speaking, mopheads are more characteristic plants of southern gardens, although they do grow along the coast up to Cape Cod and the MA islands. Within a 100 mile radius of me, you're way more likely to see them over on the Delmarva than up in Harrisburg, PA.

Thank you all! After a long tortuous process of renovating and adding onto our small house, I can't wait for March so I can dive into planting. The construction wrecked the yard so it's a blank slate.

I'm going to try some of the alternatives suggested in this thread. Except azaleas - I'm the one person in the DC area who doesn't love azaleas. We have a few and they seem incredibly hardy and pretty when they flower, but most of the year they just kind of look scraggly. That's sacrilege I guess.

We had a mammoth bunch of hydrangeas in front of the house but lost them to construction. In the back yard, the hydrangeas are on the opposite side of the yard from the walnut trees and don't seem to be impacted.

The walnut trees seem to be doing well too. We just had them trimmed by an arborist and the only problem that came up was a raccoon living high up in one of the trees!

Some ideas using plants I previously mentioned:

Would forsythia work i your area.

Seems like a perfect spot for roses.

You've got some awesome suggestions there. You might also consider:

Itea virginica or cultivars like 'Henry's Garnet' or 'Merlot'

Hydrangea quercifolia or cultivars like 'Ruby Slippers' or 'Snow Queen'

Any of the blueberry bushes indicated as excellent ornamental value in your area