Q: I have a beautiful large older tree in the yard and there are roots spreading out from it that cause problems when mowing and lay so close to the surface that sometimes someone stumbles over them. I thought a tree's roots went straight down under the tree so why is this one different? Also, can I cut these roots out without harming the tree?
A: Here are some facts about tree roots that may answer your questions:
• Almost all tree roots are in the top 2 feet of the soil and they flair out around and under the tree to create a stable base that will keep the tree upright as it grows.
• The reason they lay so close to the surface is because they must have oxygen to survive.
• As the tree grows older and larger, the roots expand to nourish it and to continue to give it stability.
• Like any of our plants, the root system controls how strong and healthy the plant is. We sometimes look at our trees differently because they are so large and complex, but their life literally depends on how healthy the roots are.
• As the tree grows and matures of course the roots swell and become larger and larger to help hold the tree upright and to supply the needed nutrients and water.
• Anytime these roots are removed or cut off for whatever reason, the tree is weakened and more than likely its life shortened. Also, trees that have this happen to them are open to disease and pests.
• If your tree is healthy, I would advise beautifying under it and landscaping in such a way that people automatically walk out around where the roots are laying on the surface. Doing this will also make it easier to mow.
• A tree will take up most or all the nutrients, water and air near and under it so if you add plant material, you need to plant shallow rooted plants and probably shade loving ones then remember to water often.
• Begin your landscaping scheme by cutting a narrow circular trench in the soil around the tree, one that encompasses the roots that are laying on the surface of the ground.
• Doing this will give you a boundary to work within.
• Find the natural areas made by the roots that have spread like fingers under the tree.
• Remove any sod in those areas around the root, then add good soil and work it in to depth of 6 to 8 inches so you can plant plants that like shade and have a shallower root system.
• Add some garden ornaments or a bench taking care not to cut or damage the roots.
• Cover the area with porous material such as mulch or stone. Remember your tree's roots must be kept fairly uncovered so they can breathe.
• Also, mulch will help the new plants retain moisture and keep grass and weeds from moving in.
• Never pile wood mulch up on the trunk of a tree or inches and inches deep no matter how young or old it is. That is just an invitation to critter and insect damage and will keep water from getting to the roots.
Jane Ford is an Advanced Master Gardener. Email questions to firstname.lastname@example.org. She also answers gardening questions with horticulture educator Ricky Kemery noon-1 p.m. the second and fourth Thursday of each month on "The Plant Medic," a radio show on 95.7fm. This column is the opinion of the writer and does not necessarily reflect the views of The News-Sentinel.