I just went out and looked at mine. I'm out by the airport. One is fine and the other looks the same as yours. The one that looks fine is more shaded so maybe our little dryer than average summer had something to do with it. The lilac at camp in Jefferson county is fine. We will just have to wait and see what happens next spring.

Mine are just fine but I water them regularly.

It's been so oppressively hot all summer I'd not be at all surprised if things not watered showed signs of stress.

Thanks both of you! I grew my little Lilac from a small rooted shoot that my neighbor gave me...finally old enough for first bloom last year and now this brown leaf & dead limb stuff...ugh.

"Functionthelook"...I'm glad you told me you were out by the Pittsburgh airport because we live so close to same area....and observed no damage to a Lilac in Jefferson Co...wonder why it's ok?

Most importantly you both mention a "hot summer" & a "dry summer" ...I thought we had a good bit of rain for a while, but then it got super hot and everything dried out, in spite of that rain I think.

And "Functionthelook" you mentioned you noticed a lilac in the shade had less brown leaves, and I also noticed that with my neighbor's two lilacs next door!

"Cerbhaill" I'm going to water regularly next year, I was afraid of overwatering and maybe didn't give it enough for that hot spot it's in.

Even if there is a virus or some kind of disease I've read you should make growing condiions as good for the Lilac as possible to help it survive.

Another question: Did anyone have any limbs force out a bloom in Autumn?! If so were they on Lilacs that looked healthy or with brown dry leaves?

Sue, it hasn't been a good growing season this year. Some are and some aren't. You know Pittsburgh, our weather is predictably unpredictable. Who knows, next year it could be one of those cold wet summers where it feels like it never stops raining. Our plants are use to wild rides and adapt.

The spring was so wet and cold, then we got a little dryer than average this summer, but not out of the norm. We were never in a drought. Our plants send out deep roots for water from the winters snow melt that stays deep. I'm no expert but I don't think the lilac branches are dead, they just went into dormancy. Lilacs are pretty hardy plants. The fall rains are back anyway now. I really hope it isn't a disease. I've lost Dutch Elm and Blue Spruce trees over the past 8 years to disease.

Once in a while I've noticed tiny blooms on my lilacs in the fall.

Jefferson county is in a different zone usually 3-5 degrees cooler and more snow melt than the burg.

This could be Lilac Bacterial Blight (LBB).

It is a disease that is common for lilacs. Especially if spring is cold and wet lilacs are prone to LBB.

Lilac Bacteria Blight

"Functionthelook" I agree our seasonal changes are pretty much all over the place, and I agree it must not have been one of the best of growning seasons- I noticed this in the performance of several other of my garden plants. And weather conditions affects viruses, bacteria and fungal diseases, and just the over all ability of a plant to deal with them. (Oh when you said out by the airport I thought you meant the Pittsburgh Airport...yes I can see Jefferson Co. is more northern than where I live.)

"Dutch" and "Functionthelook" I am sure some of the branches are bare with healthy plump buds but some are very dead with no buds and brittle.

I'm pretty sure it's not Bacterial Blight because it had no wilting of the tips as those photos show on the links you shared...thanks for sending!

I'm now suspecting weather conditions this year plus one of the Leaf Spot diseases that are of a fungal or viral origin such as: https://www.ksuhortnewsletter.org/newsletters/leaf-spot-on-lilac

It's been two years that I've seen this take place in the city of Pittsburgh.

I appreciate everyone sharing their personal experience and observations on this Lilac leaf browning going on in our area.

Any more thoughst on it? Please share, discuss.

Sue, " Oh when you said out by the airport I thought you meant the Pittsburgh Airport...yes I can see Jefferson Co. is more northern than where I live.)

I did mean Pittsburgh Airport. Findlay township to be exact.

Functionthelook,Oh thanks for clearing that up, I assumed that's what you meant then I thought you were in Jefferson County but that Lilac was at "camp" there!

Well nice to meet you!....(.I just tried to "follow" you but Houzz must not be working right, I click and nothing happens.)

My lilacs look worse than for the last month. Second year of summer dry.

I'd take a picture but it's kind of embarrassing. ;-)

"I thought we had a good bit of rain for a while, but then it got super hot and everything dried out, in spite of that rain I think."

Just because it rains in June doesn't mean you don't have to water in July.

I think all you are seeing is heat stress.

I also think that the autumn buds opening are likely a response to that stress.

But I'd stop looking for fungal issues or leaf spot issues or anything else that needs to be treated- you sound dangerously close to spraying something that is not warranted.

It's not too late to water now- going into fall healthy is your best bet at a good spring.

At any rate the foliage is mostly done for this year- scrutinizing leaves in almost October is a bad idea especially if you're prone to want to "do things" instead of stepping away and being patient..

All you can do is wait for next season and hope for better weather and remember to water deeply when nature does not.

cearbhaill (zone 6b Eastern Kentucky) I hope you're right that it's just heat stress.

And nope, I'm not one to spray chemicals on plants--, although after 3 years of progressively worse weevil damage on my S. Magnolias, beyond cosmetic- I am considering Neem oil, but afraid i don't know when to use it and not harm natural preditors, the parasitic wasps https://www.pinterest.com/simplesue/magnolia-tree-health/ that are bound to eventually find the weevils on my trees.

So true..looking back I think I should have watered more!

I'm so happy to learn you believe the autumn buds opening/blooming are reaction to the heat stress it dealt with.

As for Leaf Spot...it's still a possibility- but I'm hoping it's just heat stress as you think.

and...

BillMN-z-2-3-4 I embarassed myself with my tragic Lilac photo, show us what you have LOL!

"I'm pretty sure it's not Bacterial Blight because it had no wilting of the tips as those photos show on the links you shared...thanks for sending!"

Wilting of tips is not always present with Lilac Bacterial Blight. What is always present is that leafs look awkward i.e. misformed, necrotic, etc.

My lilacs are all doing the same thing as everyone’s that are pictured here. including the wierd autumn blooms! just noticed 5 of them. I stopped at a nursery the other day that had reblooming lilacs but they wanted $200 PER PLANT!! No thanks! Mine may turn into those, for free!! 😄 Trying to look at the bright side. Cearbhaill- mine always get powdery mildew by the end of summer also. So does the foliage on my peonies.

BillMN-z-2-3-4 You seems to really know your Lilacs well- seeing your photos and hearing how many Lilacs you have and how you didn't water the big ones, but did water the new smaller ones and how you said it happens every year does seem like it must be a water issue! Impressive how many Lilacs you have!

Rebecca/N. IN/z6A thanks for telling me your personal experience with your Lilacs having the same issues also!. Your issues with Powdery Mildew reminds of me when I bought a reduced price Peony at the end of the season horribly covered in Powdery Mildew from a nursery...I planted it and the next growing season I watered all the Peonies more than the year before and the Mildew was not an issue on any of the Peonies!

Dutch thanks for the info that Bacterial Blight doesn't always wilt the tips, this kind of info is good to know, I like learning.

What I've learned collectively from everyone's input here is how important watering Lilacs is to most likely prevent this browning of leaves and leaf loss, due to heat stress.

I will water my Lilacs more next growing season and report back with my observations on this issue on how regular watering affects them.

Thanks EVERYONE!

When they're good, they're spectacular. Very aromatic.

Here is a picture from the house window, May 2016, 5 years after they were cut to the ground by neighbors who were cleaning up after a big storm.

:^)

That is a spectacular row of Lilacs! Thanks for sharing the photo- wow!

UPDATE: Well now it's April 17, 2023 and my Lilac & my neighbor's Lilacs all look healthy again- this year I am definately going to WATER it!