Red Oak tree stress caused by car parking? - Ask Extension
We have a large red oak tree (diameter about 3 feet). Over the last few years the tree appears stressed, losing leaves at the top branches and getti...
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Red Oak tree stress caused by car parking? #278285
Asked September 15, 2015, 9:15 AM EDT
We have a large red oak tree (diameter about 3 feet). Over the last few years the tree appears stressed, losing leaves at the top branches and getting slowly more apparent. Cars are parked under the tree and the soil there is bare and hard. Could the parking of cars compacting the soil be the cause? Can this kill the tree?
Thank you.
Butch Cooper
Thank you.
Butch Cooper
Grand Traverse County Michigan
Expert Response
Cars or even a single car parked in the root zone of the tree is compacting soil. It can kill the tree.
The decline that you see now very easily could be from this activity. The tree's decline happens as pore spaces in the soil that water and air enter disappear from the weight of the vehicles. This means the tree is getting less water when it rains and the respiration for the roots cannot go on normally. Roots take in air and use the carbon dioxide and make oxygen. It can't happen with compacted soil. And don't forget any fluids leaking from these cars... that's bad, too.
The death of the tree will happen faster if the soil is clay or heavier as compared to sand, but it will still happen. Roots go far beyond the drip line of the tree. Roots may be as much as two to three times farther than the length of the branches depending on the size and kind of tree. If grass can't grow under the tree because of cars, the tree is also in trouble.
The decline that you see now very easily could be from this activity. The tree's decline happens as pore spaces in the soil that water and air enter disappear from the weight of the vehicles. This means the tree is getting less water when it rains and the respiration for the roots cannot go on normally. Roots take in air and use the carbon dioxide and make oxygen. It can't happen with compacted soil. And don't forget any fluids leaking from these cars... that's bad, too.
The death of the tree will happen faster if the soil is clay or heavier as compared to sand, but it will still happen. Roots go far beyond the drip line of the tree. Roots may be as much as two to three times farther than the length of the branches depending on the size and kind of tree. If grass can't grow under the tree because of cars, the tree is also in trouble.
