Buzz
As trees mature, their shallow roots may extend and emerge above the soil surface. This exposure can result from natural aging, soil erosion, or limited space, which forces roots upward. If you're dealing with exposed tree roots causing issues, consider covering them with mulch or an attractive ground cover. As a last resort, you can opt to remove or partially remove problematic roots. To prevent future problems, plant trees strategically and choose species less prone to surface roots.
Steps
Using Mulch to Cover Exposed Roots
Choose an organic mulch material. Applying mulch around the tree's roots can provide cushioning, insulation, and reduce soil erosion. Select a material that won't excessively absorb moisture from the surrounding soil. Some options include:
- Pine straw: Allows moisture to reach tree roots without excessive absorption.
- Pine bark nuggets: Ensure old nuggets are removed to prevent moisture retention.
- Shredded wood mulch: Use a thin layer to avoid over-absorption of moisture.
Apply a layer of mulch no thicker than 3-4 inches (7.6-10.2 cm). Ensure the mulch covers the exposed roots adequately, but avoid suffocating them with excessive mulch. When using more absorbent mulches like shredded wood, opt for thinner layers to prevent buildup.
Extend the mulched area to cover the exposed roots sufficiently. The mulched area may need to extend up to 2/3rds of the tree's canopy diameter. Don't worry about covering part of the lawn around the tree, as allowing roots to compete with grass can worsen soil erosion.
Avoid piling mulch around the tree trunk. Excessive mulch accumulation at the base of the tree can lead to bark disease. Leave a gap between the mulched area and the tree base to prevent this.
Using Ground Cover for Root Coverage
Loosen the top 1 inch (2.5 cm) of soil around the roots. Gently break up compacted topsoil around surface roots using a spading fork, being careful not to damage the roots. This preparation allows vegetation to eventually cover the exposed roots completely.
Apply a maximum of 2 inches (5 cm) of garden soil over the topsoil. Carefully add garden soil to the loosened topsoil layer, ensuring not to exceed 2 inches (5 cm) in depth. Overloading with soil can lead to root suffocation and eventual tree demise. While annual replenishment may be necessary, avoid adding more than 2 inches (5 cm) of soil per year.
Use a light application of general-purpose granular fertilizer. Adding fertilizer helps maintain tree health and prevents ground cover plants from depleting essential nutrients. Follow package instructions to lightly sprinkle 15-5-10 or 13-13-13 NPK fertilizer over the exposed root area.
Introduce a shade-tolerant ground cover plant around the tree base. Select resilient plants that thrive in low-light and low-moisture conditions. Optimal planting times are early spring or late fall. Consider options like wild violets, ajuga, periwinkle (vinca), asiatic jasmine, monkey grass, creeping thyme, or dymondia.
Preventing Root Exposure
Avoid planting shade trees too close to structures and walkways. Surface roots become problematic when they disrupt footpaths, sidewalks, and building foundations. Aim to plant shade trees at least 6 feet (2 meters) from sidewalks and pathways, and 15 feet (5 meters) from building foundations.
Opt for tree species less prone to root exposure. Rapidly growing shade trees like Arizona ash, silver maple, poplar, and willow are often associated with root exposure issues. Consider slower-growing alternatives such as linden, Colorado blue spruce, sugar maple, Japanese maple, or red buckeye when choosing trees for your property.
Implement strategies to combat soil erosion on your property. Soil erosion frequently exposes tree roots. Address serious erosion by consulting a landscaping professional to install erosion control measures. Additional steps include:
- Applying mulch or ground cover plants to bare soil patches, especially on slopes.
- Avoiding over-watering to prevent excessive soil runoff.
- Using jute netting or coconut fiber mats to stabilize soil until ground cover plants establish.
- Applying a layer of mulch around newly-planted trees to prevent erosion during growth.
Tips
Things You’ll Need
Using Mulch to Cover Exposed Roots
- Choose organic mulch like pine straw, shredded wood, or pine bark nuggets
Planting Ground Cover to Conceal Roots
- Spading fork
- Garden soil mixture
- General-purpose granular fertilizer (15-5-10 or 13-13-13)
- Shade-tolerant ground cover plants, such as violets, vinca, or Asiatic jasmine
Trimming Exposed Roots
- Garden spade
- Root saw (for larger roots) or shears or loppers (for smaller roots)
- Root barrier to prevent regrowth
Preventing Exposure of Tree Roots
- Slow-growing varieties of shade trees, such as blue spruce, linden, or red buckeye
- Mulch
- Soil-retention materials, such as jute netting or coconut fiber mats
