This summer provided a number of hot and dry weeks for both people and trees.  Many of the old, young, and soil-limited trees have been damaged.  The combination of drought and harsh site conditions provided in parking lots, along streets, on open squares, and surrounding pavement have led to a number of tree symptoms.  The old term “heat stroke” fits trees where heat loads have been extreme and caused problems.

During the drought, trees should be given a higher priority than lawns. Lawns can be replaced in a matter of months whereas a 20-year-old tree will take 20 years to replace.

Trees planted within the last three years need two to three waterings per week.  A general rule of thumb is to use approximately 10 gallons of water per inch of trunk diameter for each watering.  It’s recommended that watering be done in the early morning hours or late evenings and should continue until 1 inch rains become a regular event.

Guthrie Center’s GlaDesign Landscaping owner Larry Glade says not only is heat stress a factor, he’s seen a lot of stress this summer on maples due to construction and building work.  Panora’s Steburg Nursery owner Jim Steburg explains that when root systems are damaged by construction damage, compaction, or poor drainage, they cannot supply adequate water and nutrients for the trees growth and survival.  When this happens, often the tree is unable to produce sufficient carbohydrates and growth regulating chemicals.

Steburg says Iowan’s are planting more Maples because they are one of the most insect and disease free trees available for this area.  Iowans have stopped planting Ash trees because Emerald Ash Bore has been predicted to head this way, but it’s unclear when it will actually hit Iowa Steburg added.

Glade says he’s seen Oak Wilt and has had to remove Burr Oaks for several residents.  Glade says residents tend to grind up diseased trees and use it as mulch around their property.  They don’t realize they are transporting disease to their flower beds and Glade strongly recommends to never use diseased mulch on thriving gardens.