July 21, 2011   

Summary data for Liquidambar styraciflua, American sweet gum, branch failures

There are 5161 reports in the database. 137 are Liquidambar styraciflua (Trunk 38, Branch 96 and Root 3)

Mean diameter of branch at point of failure: 7 inches

Failure at attachment: 68%

Failure 6 ft. or less from point of attachment: 24%

Decay present: None 66%

Other defects: Dense crown 37%, codominance 20%, multiple branches at same point 13%

Note: The field "end weight Yes or No" was entered in only 38 cases, but 30 of those were Yes.

Site use: High use 68%

Pruning: None 67%

Month of Failures:

Weather: Wind < 5 mph 26%, 5-25 mph 47%, >25 mph 27%

Precipitation: None 67%, Rain 23%

Additional notes:

In many cases, trees were reported to have been heavily laden with seed pods. Also, American sweet gum is a species known to be subject to the phenomenon "summer limb drop" (Arboriculture 2004 p.429)

Typical liquidambar branch failure. Photo: B. Kempf

See Failure Photos/Liquidambar styraciflua for more.