Q.Sambucus nigra Black Lace
The leaves on all the branches from the main trunk of my Black lace Elderberry wilted literally over night. Yesterday it looked fine and healthy, today the leaves are on all branches coming from the main trunk are severely wilted. The new growth still looks fine. I have had the shrub about 8 years and this is the first time this has happened. It is growing in part shade, zone 6. What could it be and what should I do?
While most Elderberry plants are susceptible to various fungi, viruses and borers, Black Lace is particularly susceptible to Verticilium Wilt and borers. The only way to confirm if a disease is causing this dieback would be to send a sample to a diagnostic lab which you may want to do if the same pattern occurs in the next growing season.
For now, I suggest you prune back your plant to within a foot of the ground (which will encourage new growth in the spring). As you cut off the woody stems, look to see if there is any sign of borer damage on the inside of each branch. If not, then most likely the dieback was caused by a fungus or disease. Except for Verticilim Wilt, most diseases are manageable with the use of fungicides and good environmental controls.
