Got Nature? Blog

Purdue Landscape Report: Finally, spring has sprung and summer is on its way. The hot days and warm nights are welcome for us, but summer isn’t always so kind to our trees, especially in our urban forests and landscapes. Trees are dynamic living organisms that respond to external stimuli in very strategic ways and each season presents its own challenges and summer is no different.

During the summer, growth slows as some resources become limited and typically, this is water. As the summer season progresses, the likelihood of less rain means potential drought conditions. The primary responses of a tree to heat and drought are a reduction in photosynthesis and carbon assimilation rates. This translates to a reduction in energy production and food reserves. This reduction can increase vulnerability to health issues and reduced defense mechanisms against pests.

There are some key steps to summer tree care which can help trees through potentially challenging conditions in the summer.

  1. Watch the water; be sure to supplement trees with additional watering when there isn’t adequate rainfall that measures at least an inch per week. Mature trees need supplemental watering just as the younger, newly established trees. Be sure to know the symptoms of dry conditions and how much to water with more information here.

    Drought System Photo

    Drought symptoms should be monitored weekly to prevent decline and dieback during the dry months.

  2. Refresh your mulch; adding mulch to tree rings or even better, expanding them is a great way to reduce water requirements and competition for water and other resources. As trees grow, so do the roots under the tree and expanding mulching rings outward to the dripline of the crown is a great way to keep trees healthier. Also, this helps with those surface root issues as well.

    Mulch Ring Photo

    Expanding mulch rings is a great way to improve tree root health and reduce surface root issues.

  3. Don’t get bugged too much; summer brings out the best in pests too! Many mite and scale species love the heat and can cause major damage and even death to your trees. Look for signs and symptoms of scale infestations and mite damage on your trees and shrubs now. More information on scales can be found here.  Additional details on mite damage can be found here.
  4. A nip and tuck are fine; summer is actually a good time to prune as needed to meet objectives such as reducing risk, improving branch structure, and removing conflicts or improving aesthetics. Be sure to only remove what is necessary and reduce the amount of live, green tissue removal. Remember, this is what produces food for the tree. Additional tree pruning techniques are discussed in this publication.

    Pruning Photo

    Proper pruning during the summer is a good way to improve aesthetics and stability during stormy weather.

  5. Call in a professional; it is always a good idea to consult an ISA Certified Arborist for answers to tree questions. A reputable arborist trained in best practices and current research can provide the best solutions to keeping trees healthy and reduce potential risk for damage during those summer storms. Finding a qualified arborist can be a challenge itself. Refer to this website to find an ISA arborist near you.

For additional information on urban tree care, check out all the publications at the Purdue Education Store.

Planting Your Tree Part 1: Choosing Your Tree, Purdue Extension YouTube Channel
Tree Planting Part 2: Planting a Tree, Purdue Extension YouTube Channel
Tree Selection for the “Un-natural” Environment, The Education Store, Purdue Extension resource center
Tree Installation: Process and Practices, The Education Store
Tree Pruning Essentials, The Education Store
Tree Pruning Essentials Video, Purdue Extension YouTube Channel
Tree Defect Identification, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Surface Root Syndrome, The Education Store
Purdue Landscape Report

Lindsey Purcell, Urban Forestry Specialist
Purdue Department of Forestry and Natural Resources

Got Nature?