no properly prune it out.. once it leafs.. you will not see the loss .. especially in regard to the last pic ... its been a heck of a couple weeks here in adrian mi ... this aint nothing compared to some of my damage ... with no insult to the root system .... there is no reason that it can not fill in any open spots.. by fall ... depending on what type of dogwood.. i would be more concerned with the multiple days near -20 .... than this rather minor pruning concern ... prune it properly.. and be done with it ... though i didnt think one usually doesnt think to REJUVENATION PRUNE a dogwood.. but the shape of yours would lend itself to pruning under this method... google that term for youtube and guidance ... do it right.. and forget about all these voodoo remedies ... you will spend hours and many dollars.. and most likely.. end up failing.. next time you have the next ice/heavy snow storm ... a $10 invest in a good pruning saw.. and cut that branch out.. as close to the ground as you can get down in there .. no trimming at height ... get in there .... good luck .. go blue or green at your discretion ... ken

Gray Dogwoods sucker so much that they end up growing in a dense thicket. I think you could plant them 2 feet apart and be OK. In my fields the gray dogwoods stems are about 6 inches apart. I'd expect Elderberry to grow taller that Gray Dogwood and not sucker or spread as much or as rapidly. I would give the Elderberry some separation from the dogwood - don't plant a dogwood within three or four feet on either side of an Elderberry. One drawback to Gray Dogwood as a screen is that they are deciduous - in the winter they won't provide much screening. Same goes for Elderberry, which are even less effective as a winter screen because they have far fewer stems. I think you will see lots of birds eating the berries of both shrubs. Both shrubs will fruit much better in full sun than in shade. I have Gray Dogwood growing throughout the woods, but see little fruit on the shade-growing dogwoods. Same goes for Elderberry. Both need about half sun to grow much fruit. If you have lots of shade you should consider a different shrub. Mapleleaf viburnum (Viburnum acerfolium) would be a good choice, although it doesn't grow upright like Gray Dowood - it tends to sprawl.

Haven't grown silky dogwood, but have seen it listed in conservation plantings as liking moist soil. Gray dogwood, on the other hand, you see it growing wild here on very poor, gravelly soils - it springs up in roadside areas along with the red cedar. (when the fall color comes, the gray dogwood is instantly recognizable with its maroon hue.) Here in Ohio, im concluding red cedar may be the most valuable wildlife tree - the female trees have little blue berries that bluebirds and others like, offers winter cover, roosting habitat, and is where the robins build their first nests of the spring.

You can take a photo now and it will likely be IDed even without leaves. It could be either of the two small trees suggested above based on location.