Many of our established woody ornamentals can survive periods of prolonged drought. In response to drought conditions, some of our woody ornamentals, both native and exotic, can start the annual fall leaf defoliation a bit early during prolonged drought conditions. Leaves can also turn brown and curl on the edges and drop in mass quantities, particularly on species such as linden, birch, dogwood (red twig, yellow twig, pagoda, and Corneliancherry dogwoods), and hydrangeas. What can we do to help plants handle this dry situation? Water! The recommendation of 1″ of water per week per plant is very important, even in the fall. Watering is particularly important for herbaceous perennials, as their root system is not as extensive as woody tree and shrub roots.
Dr. Laura Jull, woody ornamental Extension specialist provides information about taking care of trees in a drought in this article.