Linden tree - Ask Extension
Our pyramidal linden is very sparce in foliage this year, and the leaves are full of tiny holes, as though eaten by an insect. Additionally, the trunk...
Knowledgebase
Linden tree #649916
Asked June 12, 2020, 11:57 AM EDT
Our pyramidal linden is very sparce in foliage this year, and the leaves are full of tiny holes, as though eaten by an insect. Additionally, the trunk is full of linear holes that would appear to be from a woodpecker or sapsucker. We cannot see any insects, worms, beetles or other pests, and there doesn’t appear to be any sap or sticky residue on the leaves or trunk. This is in Fargo.
County North Dakota
Expert Response
Thanks for your question, and for sending the photographs. There are two factors present that are currently affecting your linden tree. First, the holes in the leaves are most likely from the feeding activity of cankerworms, which have been present again this spring and early summer. Because these caterpillars progress on to other stages of their lifecycle, spraying early is necessary for damage control, but the cankerworms often go unnoticed until their feeding makes damage obvious. Here is an excellent publication from North Dakota State University that describes cankerworms, their lifecycle, and recommended control. Up to a certain point, trees can tolerate leaf-feeding insects with little affect on tree health. https://www.ag.ndsu.edu/publications/lawns-gardens-trees/cankerworms-in-north-dakota/e999.pdf
The second issue which could also be causing a thinning canopy is the activity of sapsuckers, or other woodpeckers. Sapsuckers create holes in fairly neat rows in the trunk of the tree, which damages the tissue that conducts water and nutrients up and down within the tree. Because these holes cut off a certain percentage of the tree's life support system, thinning of the tree's foliage canopy often results. If the holes are numerous enough, trees can die, which is why early detection is important. To break the sapsucker's habit, and encourage them to move elsewhere, wrap the area of activity with burlap or window screen. Scare-type objects can sometimes help, such as Mylar balloons or aluminum pie tins hung from branches. To help speed tree recovery, let the hose run slowly around the tree's canopy dripline during summer dry periods, watering deeply every 7 to 10 days. Prevention of continued activity is a key to keeping the tree healthy. Good luck with your beaufiul tree.
The second issue which could also be causing a thinning canopy is the activity of sapsuckers, or other woodpeckers. Sapsuckers create holes in fairly neat rows in the trunk of the tree, which damages the tissue that conducts water and nutrients up and down within the tree. Because these holes cut off a certain percentage of the tree's life support system, thinning of the tree's foliage canopy often results. If the holes are numerous enough, trees can die, which is why early detection is important. To break the sapsucker's habit, and encourage them to move elsewhere, wrap the area of activity with burlap or window screen. Scare-type objects can sometimes help, such as Mylar balloons or aluminum pie tins hung from branches. To help speed tree recovery, let the hose run slowly around the tree's canopy dripline during summer dry periods, watering deeply every 7 to 10 days. Prevention of continued activity is a key to keeping the tree healthy. Good luck with your beaufiul tree.
