Cypress Knee Problem Between Tree Bed and Plant Bed in Front of House

Question

15 Yr Old Bald Cypress Jim,

I have read your posts on what to do about Cypress knees and have talked to or read posts by three arborists about what to do as well.

Some agree with you and some do not.  I'm trying to figure out what is best for the 15 year old Cypress tree in my front yard planted in a tree bed in the center of yard.  As the attached picture shows there are many exposed knees between the tree bed and the plant bed in front of the house causing extensive brown spots in the yard.  There are numerous knees elsewhere in the yard but most are concentrated in the area I just described aa can be viewed in the picture and fall under the canopy of the tree.

Is it safe to saw off knees level to the ground that are located under the tree canopy?  I have been told (1) yes it is ok for the tree, (2) it is only safe to do this for knees beyond the canopy of the tree, and (3) doing this will damage the tree.

I have also been told that the knees can be grinded down, just like you would grind down a tree stump.

Bottom line is that I don't want to damage my beautiful cypress, but need to do something for the yard rather it be getting rid of the knees and laying down new grass or perhaps putting in a big mulch bed with ground cover around the tree to cover the knees.

And even though this hasn't been a problem thus far, I do not want to encounter foundation problems down the road with this cypress tree.

Thank you.

Laurie Kudla
Dallas, TX

Answer
Yes it is safe  to cut off the knees to ground level no matter where they are located around the tree.  The knees are expansions of the root system and I have not heard of or seen grinding of these below the soil surface. I would think it would be ok IF you do not go into the main root. damaging the roots could cause problems in die back of the foliage. You could cover the cut knees with re-sod (not more than 3 inches deep) and re-sod the area however I think the main problem seems to be the area is in the shade and grass will not grow well there. IF this is the case I would go with the Mulch bed. Beware that the knees more than likely will grow back (new ones not necessarily the old ones) and if so the mulch bed could be left alone with the knees growing there. OR maybe plant a ground cover that would grow in the shade and not need any maintenance.  I would check with your local nursery for a shade loving ground cover.

You did not say how far the tree was from the house foundation--the roots will spread about 1 1/2 times the width of the branches so you can gauge the closeness and if the roots will get to the foundation by measuring the width. You can install barriers along the foundation to stop the roots. Sounds like the tree is too close to the house. Bald cypress can grow large  50 to 70 feet in height with roughly 30 foot spread with the roots spreading to about 45-60 feet from the trunk. Here is a web link to root barriers. But i do not think that the knees will form below the foundation and cause any problems. IF the branches are reaching the house this will cause more problems than the roots by rubbing the house. http://www.4specs.com/s/32/32-9452.html