Question
I have a 30 foot Cyprus tree in my back yard that has so many knees that it's almost impossible to walk.  Is it OK to grind the knees to dirt level without killing the tree.   Or, is there anything else I can do.   I抎 hate to take the tree completely down as it acts as a golf ball shield for my house..

Answer
The "cypress knees" usually only develop when grown in or near water for most of the year. In wet soil conditions, the bald cypress will form sections of root growing above ground to gather oxygen. The size of cypress knees on an individual tree is directly related to water level. They can grow as tall as 36 inches depending on the wetness of the soil but normally are about 5-12 inches tall. The function of cypress knees is some what mysterious.  They were thought to aid the roots in gas exchange under flooded conditions but removal of the knees seems to have no ill effect on the tree.

About all that can be done is cut the knees at ground level. This will not harm the tree but will need to be done again as new ones grow later. Do not use a herbicide like Roundup it will kill the roots and the tree.