Common Diseases of Lilacs. Although lilacs are a hardy bunch, they can succumb to problems like any other landscape shrub. Be on the lookout for these diseases For perfect Lilac hydration, water deeply every 10-14 days, allowing the soil to dry out in between. During peak bloom, Lilacs are thirstier—give them 1 to 2 inches of water weekly. Plant Care Guide > CommonProblems > Commonlilac 'President Grevy'.The Commonlilac 'President Grevy' thrives best in well-drained soil with a pH between 6.5 and 7.0. Powdery Mildew on lilac; Ward Upham, Kansas State University, Bugwood.org. There are commonproblems that routinely plague lilac. CommonProblems With Lilacs. Lilac shrubs are typically not problem plants in the garden. But they can encounter a few common issues. Poor Flowering. CommonLilacProblems. Low Flowering. Heat Intolerance. Poor Aging. Common Pests & Plant Diseases. Bacterial Blight. With summer comes lilac leaf spots, and commonlilac often sees a lot of leaf damage starting in summer and intensifying into September. Common diseases that cause these problems... About Lilacs. The commonlilac, Syringa vulgaris, is well loved for its toughness, reliability, and fragrance. Lilacproblems. There are a couple of commonproblems with lilacs: Poor flowering in spring could be due to poorly drained soil or not enough sunshine – lilacs need a sunny spot. Of the 20-plus species of lilacs, two derive from Europe and the others are from Asia. The commonlilac (Syringa vulgaris) originated in eastern Europe. Lilacs are generally easy to grow and have relatively few major problems. Regular maintenance and careful pruning are the first line of defense in avoiding problems with lilac bushes. There are a number of cultural problems for lilacs, such as verticillium wilt and lilac witches' broom. Compare your lilac to lilac tree disease pictures online to determine the problem. Lilac Disease Problems. Lilacs are susceptible to a couple of plant diseases. The most common is powdery mildew. Commonlilac is susceptible to a number of additional disease problems including blights, leaf spots, wilts, ring spot virus and honey fungus. Potential insect pests include scales, borers...
