Landscape Report


Summer Tree Care

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 forest 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.
  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.
  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.
  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.


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