A borer in my elderberry

Chris Reher
last month


Worried about my 3-year old black lace, zone 5b

I noticed last summer that some of the newly formed, green, branches in the spring (those about 4-6 inches long) droop down as if utterly wilted, while those nearby are fine. This is going on again now. I then realized that this shrub is supposed to look lush and full, and not like a bonsai masterpiece.

I took a closer look and found a hole in those twigs, so obviously the work of a borer.

I found a reference to the Elderberry Borer, but articles describe that bug as laying eggs near the base of the plant from which their offspring bore down into the roots.

This damage is at the tips. I cut off the affected parts, about 20 or so tips, but I doubt it's that easy.

I found much oohing and ahhing about how pretty the elderberry borer is, but no info on how to get rid of it. If these things chew on roots, I can't see this shrub surviving much longer.

Could it be something else chewing on my black lace or am I stuck with this?

Comments (5)

  • ken_adrian Adrian MI cold Z5
    last month

    sometimes its easier just to get rid of a problem ...

    how about some pix???

    if this happened last year.. why do you think its an ongoing problem ...???


  • Chris Reher, z5b
    last month

    Hi Ken

    Not sure what you mean. Having new growth on a shrub wilt two years in a row does appear to be an ongoing problem, no?

    Here are some pics. I cut most of the wilt away yesterday. Some stems had a single hole near the base, others did not. This is a small example, the only one this morning. As you can see, I already clipped it back once, but must have missed whoever is living in there.

    Looking at the entire plant, it doesn't look at all as it should, eh? It is early, but should I have that much bare space?

  • Deb
    last month

    Borers like to burrow into the pith of the branches and trunks. They attacked my Tiger Eyes sumac. I cut the damaged branches down to healthy pith, then sealed them with nail polish. You could probably use carpenter's glue, as well. Haven't had any more problems with borers on that plant. Here's more detail.

  • Chris Reher, z5b
    last month

    That sounds pretty hopeless, Deb :( I can see the point of cutting back to healthy wood, but surely there are more of those grubs burrowing around this plant.

    I don't really get the science, either. If the eggs are laid around the base and bark of the tree, why a I seeing holes and damage at the tips? Is that where the tasty bits are? This is so very disappointing but I'll go ahead and get radical with the pruning

  • Deb
    last month

    I don't know about the tip situation. I did have another Tiger Eyes sumac that had borer holes at the base of the trunk. So I cut it down and sealed the top of the trunk. Then I planted the rootball in potting soil in a large pot just to see what it would do. Leaves and branches started sprouting after a while, so I transplanted the rootball back into the ground. Now it's a lovely plant. Don't know whether it would work for your tree.

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