Dying lilacs

[juniperhillfarm]

Not the best time of year to diagnose problems, but I had trouble with Tinkerbelle Lilacs this year and just found this forum.

I prepped 2 new beds and planted 14 container plants (Penn Pride). They were well tended and watered.

1 shrub started showing shrivelled leaves which then died, the entire branch then died, and then slowly the entire plant died the same way.

This fall, a second plant started showing the same signs, and by late fall this second plant had expired.

I saw no sign of mildew, and all the surrounding plants looked healthy. I could detect no obvious pests or borers.

I worry about the rest of them, any thoughts on what might have caused this? I know I can get them replaced, but I worry about it as this is an important hedge in our garden.

Thanks,

Paula

[grandpasrose]

Hi Paula! There is no such thing as a bad time to talk about gardening - anytime!!
It sounds to me like you have a case of either fungal or bacterial blight or wilt. Lilacs are prone to this.
You need to remove all infected material, including the entire dead plants, and destroy them - don't add them to the compost or you will just spread the disease around!
Then, because you have them planted in a hedge, you can't just move your plant to somewhere else, so I would suggest removing as much of the soil that these two bushes were planted in and replacing it, just in case some of the spores are still remaining.
Also, to eliminate and/or prevent it from spreading to your other bushes and the new ones you replace, I would spray them weekly with Neem Oil. You can get this at your garden centre.

Hope this helps - let us know how it goes, and feel free to come back anytime!!

Val

[The Helpful Gardener]

Good call GR; it's probably the latter, bacterial blight and it's very common now for any number of reasons. It is now commonly used on apple crops as a bacterial counterculture against fireblight. Doesn't hurt apples but it's h*ll on syringa.

But the most common reason is poor growing habits at the nursery; it is common where lilacs are massed with little air circulation (like production nurseries), It's characterized by a blackening at the edge of the leaf (often where they are damaged by late frosts or sucking insects). Check those branches before writing them off as dead; cold weather can kill the pathogen and I have seen branches come back. But remember that this is a bacteria not a fungus; many people make matters worse by spraying for fungus which is not great for an already stressed plant...for the homeowner the best method is destruction, cutting off diseased branch (all of it). Make sure to clean up those pruners after EVERY cut with alcohol (I like swabs for my pruner and Pappy Van Winkle 20 yr. old bourbon for me )

HG