Sorry to heat that. If you pick the leaves off and get rid of them, all of them, this will prevent the moth(s) from coming back. The amt of damage is usually small IF the numbers of bugs is small and the moths are not allowed to do their thing. But it sounds like they have and they infected several plants. When things get out of control, you may need to spray Bt, Bacillus thuringiensis kurstaki (DiPel, Thuricide, etc). I would suggest -next year- applying it again but, do it earlier than when you first detected the problem this year. The damage is typically cosmetic and I guess it would rarely kill a hydrangea. But never say never, hu?

Regarding the question, yes, you could also cut off all the stems down to the ground if the infestation is large and removing all the infected leaves appears impractical. It is best to prune when the plant is dormant so the plant does not try to generate new growth but, I understand that times are not normal. If you prune all stems, I would still apply Bt next year. And yes, this will produce weak stems for a while.

My understanding of the information online is that this overwinters on the ground in the pupal stage so cutting it back dormant won't do any good. All control measures mentioned seem to target the window when after the eggs hatch, but the larva haven't done too much damage.

https://www.torontogardens.com/2017/05/whats-wrong-with-my-annabelle-hydrangea.html/

luis_pr --- I am here in SE Michigan. We just cut back our Annabelles (not leafed out yet). When would I apply the Thuricide? When it starts leafing out? Now? Both?

If you had the problem in July last year, for example, I would apply it in early June. The shrub should have leafed out by then. Basically, apply it at the first sign of the infestation and repeat per label directions to maintain control. Thorough coverage of the leaf surface is best so I would not apply when it is leafless unless you see something. Same for Bt.

How come you cut your Annabelles so early? Did you mean to say that you cut the dead wood at the end of winter?

luis_pr -- we cut them back in March here in Michigan. No where near leafing out yet. Provides some "winter interest" to do it then versus the fall. BTW --- it is starting to leaf out now slowly. We did spray the Bt but still got the leaftiers. Picked them off and continuing to spray once a week. At least we caught it early this year. Last year, I had no idea what that was and my Annabelles looked pretty bad.

Ah, I was thinking the same... that they would not be close to leafing out yet.

It’s that time again! Every year I tell myself I’ll be on top of this before the nasty little larvae come back, and every year i’m too late. My annabelles are still leafing out and some leaves are already stuck together!! I spent 30 minutes this morning hunched over, peeling leaves apart and squishing those gross little things. Now my back hurts. Ugh!!

If you have a smartphone, put a reminder in it or on your PC. Otherwise. put a written note in December 2022 wall calendar to put a reminder in April 2023’s in the new 2023 calendar.

Great idea, luis! I’d actually been thinking about getting ahead of this, but because we had a ”late” spring, I thought I had more time - my Annabelles don’t even have all their leaves yet, for crying out loud. I ordered some spray off Amazon, and I’ll get to it as soon as it arrives.

Part of me wonders if I should just give Annabelle the heave-ho. Between these nasty little larvae every spring and the summer rainstorms that leave my Annabelles with hanging heads before they’re even at their peak, I’m getting flustered. My paniculatas give me no trouble at all.

That is a thought but nothing is perfect. Some paniculatas can have heavy blooms that flop by the summer and some show their feet by yellowing lower leaves in the summer.

All right!!!

i bought the Bonide Bt spray, but didn’t use it this year, as I’d already squished dozens upon dozens of larvae.

But….i will definitely use it next year on my Annabelles, so happy to see you had success with it, @stir_fryi SE Mich, that’s awesome and gives me hope for success next year!!

Bumping this post!! I’ve got my BT spray and I did a first application this evening. I’m going to apply once a week for the next few weeks and hope it makes a difference.

Good luck! Someone sent me a picture of a possible case already.

Not sure how well the Bt spray is working. i’ve been spraying once a week for the past three weeks, but still have several stuck-together leaves. So I continue to pull the leaves apart and squish those nasty little caterpillars.

Honestly getting tired of my Annabelles and their post-rain, droopy, water-logged blooms. I could deal with the springtime caterpillars if they were trouble free and beautiful for the rest of the season, but they’re not. Getting ready to give them the heave-ho.

Im in SE MI too. Just checked mine tonight and i had about 9 stuck together leaves on three bushes. i guess I’ll spray one more time.

I ended up buying the bt concentrate and a large pump spray bottle - so much less expensive that way. I only mix up what I’m going to use that evening.

I think this is it for my Annabelles (and I have about 15 of them). If we get a summer rainstorm this year that ruins my beautiful blooms before I can even enjoy them (which has happened the last three years), I’m done. They’re becoming as much work as my roses! :-/

Just went out for another check; squished a few this time, but if i’m remembering correctly, much MUCH fewer than last year. I think I may have actually had hundreds of stuck together leaves in previous years. So maybe the bt IS working! i am feeling a little hopeful, at least. Good luck, stir-fryi!!

Had to cut ALL 5 of my Annabelle’s down. They must have been 20yrs old.
Was told they will come back next year but I actually don’t want them too.
They’re too fussy for me and heavy.

I’ve been told the best new replacements for the Anna’s are the new “Incrediball” variety or “Limelight”.

Our “Quick Fire” bushes look gorgeous EVERY year with ZERO problems as does our “Limelight” Tree and bonus the deer do not touch those ones either here in SE Mi!

I’m sorry you lost your Annabelles. Incrediball gets leaf tier infestations the same as Annabelle…and I find them to be just about as floppy after a hard rain. I have both, but just call them all “Annabelle”…they’re the same to me.

And deer will definitely eat both Quickfire and Limelight, as well as Little Quickfire, Firelight, Firelight Tidbit, and Oakleaf Ruby Slippers. They eat them all, and the only thing that helps for me is a liberal spraying of Bobbex once a week.

Interestingly, I found some of those nasty little larvae on my paniculatas too, on the Firelights located adjacent to Annabelle. Just a few, which I quickly dispatched. They must be getting desperate for a host!!

Incrediball and Invincibelle advertise stronger stems and-or larger booms but they are not immune to flopping. I have seen plenty of them with the same problem after rainfall/storms in the summer, especially after they bloom and get top heavy. Limelight or panicles will do best in full sun there but in more sun exposure than the other smooth hydrangeas. But I caution that deer to like panicles so do not assume they will skip a hydrangea just because it is a panicle hydrangea. Best to apply deer counter measures always and flopping counter measures for smooth hydrangeas always.