Question
I live in Alabama.  My lilac was doing great all summer but now the veins in the leaves is dark, what is causing this & how do I treat it?

Answer
Dear Michelle, It sounds like your lilac has iron chlorosis, which is easily treatable.  Usually when the veins of the leaf are dark and the rest of the leaf is lighter colored, it is an indication that the plant is in need of iron and this is very common with lilacs.  I would simply buy Ironite and apply it to the plant.  It comes as a granule to apply to the soil and also as a spray.  I would use the spray and apply directly to the foliage as it will help it green up better.  You should see results very quickly.  This condition is common in plants like lilac and gardenias and it will have no lasting effect.  Good luck, Melissa