Roots belong underground, right? Most of the time, yes. And most of the time, if a plantБs roots are exposed to light, theyБll grow away from it and go back into the ground or mulch to protect themselves from that light. So why do some tree roots grow at or slightly above the soil surface where they can trip people, mess up equipment, buckle sidewalks and driveways, look out-of-place and unattractive, and generally drive homeowners and grounds managers to cover, smother or chop them? The thing is, roots are opportunistic Б growing wherever they find soil with adequate space, oxygen, water and nutrients. ThatБs generally in the top few inches to top few feet of soil, depending on soil type and compaction. (They go shallower in compacted clayey soils, but deeper in uncompacted sandier soils. )
Roots are also easily directed. If they hit something they canБt penetrate, like rocks, foundations, paving, pipes and other hard objects, theyБll be deflected. But if these supposedly nonporous objects have holes or cracks in them Б and if those holes or cracks offer paths of least resistance, and if those holes or cracks provide paths to soil with adequate oxygen and moisture Б then thatБs where the roots will grow. ThatБs how roots end up in pipes, as well as cause cracks and buckling to sideways, driveways, roads and other paved surfaces. As trees grow aboveground, youБll see the trunk getting taller and wider each year. Likewise, roots growing underground grow bigger Б such that over time some of the shallowest roots may simply grow large enough to break the soil surface.
Combine normal root growth with soil erosion, and youБll see lots of roots Б especially on hills, riverbanks and aboveground. So what do you do about those pesky roots popping up in your yard? Should you cover the offenders? Yes and no. Riparian species Б those that grow along bodies of water, such as river birches, sycamores, pin and willow oaks, and red maples Б are tolerant of some fill over portions of their roots, but people tend to overdo the БsomeБ part. Generally, you should avoid covering roots if what you intend to cover them with is soil. While an inch or two of soil atop just a few roots wonБt kill a tree, many trees species are very sensitive to soil level changes, including natives like beeches and white oaks. ItБs best just not to do it. A better solution for dealing with surface roots is to cover them with mulch. Any mulch will do, from recycled wood chips to pine bark and needles, but just 2-3 inches of it Б no mulch volcanoes! Another suggestion often offered when it comes to covering surface roots is to plant groundcovers around them. This solution may or may not help the situation. If only a small portion of the roots will be damaged or impacted in any one year as the groundcover planting holes are dug, and if the groundcover is perennial, then this solution is generally acceptable. Surface roots can be problematic to people and equipment, but without a good healthy root system, your trees canБt survive and grow well.
Covering roots is one way to deal with them but only if the covering (preferably mulch) is shallow and porous, allowing water and gases to be exchanged between the air and soil. January 18, 2018 >Hi there, Olivia. Oh no! Unfortunately, there is no way to repair the cut surface of the root. The tree may seal off the wound as best as it can. If only one major root was cut, and the other roots are intact, the treeБs health may not be severely impacted. To ensure the tree stays healthy, keep the tree well-watered during periods of drought and apply a few layers of organic mulch. Hope this helps, Olivia! January 12, 2018 >HI, I actually live in Nairobi Kenya but cannot find an arborist here. We have a huge Jacaranda tree in our back years. it must be 50 years old. We are having someone build a fort around it and today he unknowingly (meaning he didn t understand) cut through a major root, probably most of it. The root is only a few feet from the tree. WE are sick about it. Can you tell us what to do? Can we save the tree? Will it die? the root is probably 14 inches around. Can we seal it or heal it? We are devastated we might lose the tree. any advice would be great and so appreciated. Kindly, Olivia October 12, 2017 >Hi, Chin. The best advice for construction and trees is to keep as far away from the trunk and main roots as possible. Numbers can get arbitrary, but the closer you get to the trunk, the more damage you will likely do. It should be noted that tree roots extend far beyond the canopy and even 10 feet.
Try to minimize the excavation. You may also ask an arborist about potentially using a chemical which contains phosphorous acid which, applied before or after, may help the tree recover from the damage. Hope this helps, Chin. October 12, 2017 >Dear Sir, I plan to add some new living space at my 60 ft. wide backyard and need to do some level grading. There is a 16 in. high and 60 ft. wide retaining wall in my backyard that is about 11 ft. from my backyard fence. The plateau behind the retaining wall is at the same height as the retaining wall, thus the plateau is 16 in. higher than the rest of the backyard. There is a big aleppo pine tree at the plateau behind the retaining wall. The tree is about 80 ft. tall and 40 in. in diameter. For the level grading, I plan to dig the ground by 2 ft. deep for the whole backyard area which will be 60 ft. wide and at a distance 8 ft. from the retaining wall. Since the aleppo pine tree is located at 2 ft. behind the retaining wall, thus the shortest distance of digging is 10 ft. from the tree. Note that I will not dig the ground around the tree but only on one side of the tree separated by a 16 in. retaining wall. I have consulted with three arborists, two said I could do it, one said I canБt dig an area of 20 ft. wide directly in front of the tree even at a distance of 10 ft. from the tree. One arborist strongly suggested that I should ask him to coordinate with the construction contractor to excavate the ground, and he will clearly cut the roots using some special machine.
Please provide me your advices, I really want to save the huge aleppo pine tree. Thank you very much and best regards, Chin Ma October 4, 2017 >Hi Cynthia. We recommend using general TLC Б mulch and proper watering! Depending on the size of the root, this may not even be an issue. If the root was larger than 1/3 of the diameter of the trunk, then the tree could be shocked. Either way, though, the tree should recover. If you are still fearful for the health of the tree, we recommend having a Davey Arborist inspect the tree. Hope this helps, Cynthia. October 3, 2017 >My husband was shredding tree stumps, he wanted to shred a stump that was up against a maple and he accidentally took off a large maple root very close to the base of the tree. Is there anything we can do so we won t lose the tree. It s a beautiful tree. September 26, 2017 >Hi Bob! River Birch trees are generally not known to regenerate, so it should not grow any longer. Here if you have any other questions, Bob. September 25, 2017 >If I have river burch tree cut down to about leaving about a two foot stump to use to plant flowers in will this kill all the roots that were growing under ground?? September 9, 2017 August 11, 2017 > Hi there, Clyde. If you are asking for us to come out to your property for an inspection, unfortunately, Davey Tree doesn t provide residential tree service in your neck of the woods! In the meantime, hopefully you found our blog article helpful, Clyde. Here if you have any other questions!