Lilac "disease"

[noleymae]

One lilac in the middle of a row of nine ( all about 12 years old) has developed a serious problem. Around mid July I noticed the leaves were significantly lighter in color than the other trees. It also had no sign of powdery mildew...the others all do...and do every year. I spray with a standard fungicide. Very soon the leaves developed red veining and began to fall off. The condition has gotten worse. No sign of scales or other insects. We have had a very wet summer here in Western MA. Can anyone help me? I'm afraid it might be something that will spread to the rest of the row. Thanks, June

[Newt]

Hi Noleymae, Not sure what a "standard fungicide" is, but why are you spraying? If you are using this fungicide for the powdery mildew and the shrubs are still getting it, then the fungicide isn't working. Here's an environmentally way to control powdery mildew. You can use any one of the first three. http://www.dirtdoctor.com/view_question.php?id=204 As to your ailing lilac, I'm wondering if the plant is suffering from chlorosis from improper ph levels. I live in Maryland and the soils on the Eastern seaboard tend to be acidic. Lilacs prefer a more alkaline soil. You might want to test the soil for ph where this shrub is located. If necessary, add a cup of lime around the base of the shrub and mix into the soil. Take a look at this site to see if it helps. http://plantclinic.cornell.edu/treeshrub/lilac.htm Here's some other helpful sites on lilacs. http://www.heardgardens.com/lilacqa.htm http://www.heardgardens.com/basicsforlilacs.htm http://lilacs.freeservers.com//lilac_tips.html Hope this helps, Newt