Got Nature? Blog

Carpenter ants are very common inside trees, especially on larger, mature trees that are hollow with cavities. They nest in rotted, decayed wood, although some nests may extend into sound heartwood in the center of the tree. Carpenter ant presence is an indication of rotting wood, and infested trees should be checked to determine whether the rot has weakened the tree enough that it has become a risk of failure.

Carpenter ants in trees are not directly harmful to the tree. Control is not necessary for the tree’s health; their presence indicates decay in the tree, and they only feed on dead wood fiber. Wood decay can set in if moisture is present; it is the wood decay that gives the carpenter ants the opportunity to colonize the tree. Carpenter ants use knots, cracks, holes and old insect tunnels to gain access to these areas.

Control of carpenter ants inside trees is difficult but can be done as a way to reduce invasion of the ants into adjacent structures and places where they are unwelcome. It is also possible for ant colonies located inside trees to form satellite colonies inside a nearby home wall. Available controls are not likely to permanently rid a tree of carpenter ants, so retreatment every year or so may be necessary. Dust insecticides (such as Sevin or Abamectin) labeled for use on trees in the landscape are suggested for control. Apply the dust directly into the nest cavity.

Sealing tree cavities or treating tree wounds with wound dressings is not advised. Such treatments are unnecessary and will not eliminate nor prevent decay or carpenter ant activity. Also cutting down otherwise viable trees that happen to be infested with carpenter ants is generally not necessary unless the tree poses a risk.

Resources:
Household & Structural, Department of Entomology, Purdue University
Who Let the Bugs Out?, 4-H Purdue Extension – Entomology
The Space Invaders of Summer, Purdue Agriculture News
Report Invasive Species, Purdue Invasive Species
The GLEDN Phone App – Great Lakes Early Detection Network
EDDMaps – Early Detection and Distribution Mapping System (Report Invasives)
Subscribe – Purdue Extension-FNR YouTube Channel, find videos for wildlife, forestry, urban forestry, community development and more.

Lindsey Purcell, Chapter Administrator & Master Arborist
Indiana Arborist Association

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Tree roots wrapped around tree trunks or the lower stem can be very troublesome for tree health and safety. Stem Girdling Roots (SGR) are very common in maple trees and can eventually compress the stem so greatly that it creates a situation where the tree can be more prone to windthrow or blowing over. Additionally, it reduces the flow of water and nutrition to the tree, causing a slow decline and eventual death if not corrected or unable to be treated.

Roots that are not directed away from the trunk causes serious issues, and oftentimes, there is no good rescue treatment or mitigation of the issue.  If the tree is small or juvenile and the roots have NOT compressed the stem, careful pruning of the circling roots can be accomplished. If these circling roots are less than one-third the trunk diameter and they can be removed without damaging the trunk, then carefully cut and remove them. This will stop the circling habit and allow roots and trunk under the girdling root to develop in the proper way. Some arborists have removed larger girdling roots with no adverse effects on the tree, and they often respond to removing girdling roots with increased vigor. However, roots that have embedded themselves into the trunk or stem should be left alone. There are no guarantees with this risky process. Any time roots are removed, there is a danger for reducing stability and health.

I would suggest contacting an International Society of Arboriculture Certified Arborist to complete the task and ensure the best possible results.

For resources on tree care, view FNR Extension Publications.

Resources:
Stem Girdling Roots, Purdue Landscape Report
Trees and Storms, The Education Store, Purdue Extension’s resource center
Tree Risk Management, The Education Store
Planting Problems: Trees Planted Too Deep, Video, Purdue Extension – Forestry and Natural Resources YouTube Channel
Planting Your Tree Part 1: Choosing Your Tree, Video, Purdue Extension YouTube Channel
Tree Planting Part 2: Planting a Tree, Video, Purdue Extension YouTube Channel
Tree Appraisal and the Value of Trees, The Educational Store, Purdue Extension resource center
Surface Root Syndrome, The Education Store
Iron Chlorosis of Trees and Shrubs, The Education Store
Tree Pruning Essentials, Publication & Video, The Education Store
Cold Injury to Trees, Got Nature? Post, Purdue FNR Extension

Lindsey Purcell, Executive Director
Indiana Arborist Association

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