Will installing a new foundation deprive nearby trees of nutrients and moisture?
Question:
We have a camp in Livermore that is poorly supported and needs a foundation. Our problem is we have several mature pine trees squeezed between the camp and the pond that we do not want to endanger. If we put a foundation over the area where the tree roots extend, are we going to be depriving the trees of some nutrients and moisture, or will they move through the soil underneath the foundation? The concrete would begin about 12-15′ from the tree trunks. I know this isn’t a typical ‘gardening’ question, but am hoping you might have some insight into our situation.
Answer:
Marjorie Peronto, Extension Educator
Thanks for your great question. I’ll start by saying that yes, with the construction you are proposing, you will be disrupting tree roots, and this will impact the trees’ ability to absorb water and nutrients. The question is, to what degree, and can the trees recover? The reality is that most tree roots are very shallow; 80 to 90% grow laterally in the top 12 – 18″ of soil. And typically, tree roots extend two to three times wider than the drip line, so they are probably growing underneath your camp.
If you decide to proceed with putting in a foundation, just do your best to minimize tree root disruption. Avoid compacting the area by driving over it repeatedly with heavy equipment. Keep the trees well watered all season, especially if we experience drought like we did last summer. You may want to hire an arborist to consult with you on best practices for keeping the trees healthy. Here is a list of licensed arborists in the state of Maine.