The red and yellow twig dogwoods show their color best on first year growth, so most people cut them back to stubs in the spring. No flowers this way, but you're not growing them for the flowers but for the winter show. Growth will be quite dense then.

I grow Cornus 'Arctic Fire' this way, a newer type that doesn't sucker. Very nice.

google REJUVENATION PRUNING OF FLOWERING SHRUBS ... which is a constant ongoing pruning system ...

the key is cutting 1/3 of the stems off as close to the ground as you can get them ...

what has happened ... is that yours were sheared AT HEIGHT [probably to make them more salable]... and at every cut.. two or more buds broke.. and as they grew.. the weight at height.. is causing them to collapse ..

i am doing this right now.. on various shrubs ... and EVERYTHING that can not hold itself up.. is being cut to the ground ...

and it doesnt matter what they look like after they are pruned.. its all about the future growth habit ..

you will not be able.. to kill them.. so put that out of your mind ...

and these are NOT plants.. that 'need' to be fed ... and if they are.. you will just have more problems ....

ken

Ok, thank you. I will plan to prune them asap. 1/3 of the stems...

Rejuventaion pruning is somewhat different than is what is commonly done with shrub dogwoods and is typically used to rejuvenate old or overgrown shrubs. And only certain kinds at that - not all shrubs will respond to rejuvenation pruning equally.

Shrub dogwoods - and other shrubs often grown for stems or stem color - are very commonly stooled or coppiced. That is, they are cut back hard - all stems - to just a few inches above ground each season, usually at the end of winter or early spring before bud break. This practice tends to produce a lot of straight, brightly colored stems and promotes a dense growth habit. You miss the flowers by doing this but you will keep the plant at a compact, manageable size and with emphasis on the stem features. Shrub willows are often treated like this as well, as is ghost bramble.

I agree with Laceyvail and Gardengal - cut the whole plant back to ground level or just about. I've done this on a variety of plants including shrub dogwood right after blooming and all have ground out nicely as they commented on.

Marshall