Aurea Dogwood Problem
I have a Aurea Dogwood that is approximately 16 years old. About 10 days ago I pruned out a few dead branches which looked like they had fire blight. This week approximately one half of the shrub fell over, like the base can no longer support the stems. Any idea what caused this? Can I prune out the stems that are laying on the ground and if so, should I disinfect my tool after each cut? Will the rest of the shrub do the same thing? Should I just totally cut it back? Thanks! Kate
Ramsey County Minnesota
I can find nothing that states Cornus alba 'Aurea' - or any of the dogwood shrubs here in Minnesota - is susceptible to fireblight. There are other issues with dogwoods, but from the pictures, it looks like the plant could use a good pruning. The dead branches you found may not have a disease, but are just older branches.
One of the best features of dogwoods is the stem color during our long winter months. The younger stems have the best color, so remove the the largest "trunk-like" stems. Use a sharp, clean lopper or tree saw (tool depends on the girth of the stems you are removing) and cut the stems as close to the base of the plant / ground as possible. This will open up the plant - it will look smaller and thinner -and it will allow sunlight to reach the younger stems that have been covered up by these large branches. They will grow and fill in.
Prune as soon as possible so the new growth has a chance to harden off before winter. Next spring If you see dieback on the branches, cut it back into the living plant tissue about 1/4".
Take this opportunity to also clean up the plant base and around it. Remove dead leaves, dead stems, etc. Water it well (depending on rainfall). Mulch around the tree to reduce damage from your lawnmower / weed whip and to hold in soil moisture and moderate soil temperature preventing freeze-thaw damage especially in late winter.