How to Plant Trees Near Leach Fields

Plant shallow-rooted trees that are excessively water-loving. The underground perforated piping system can be 6 inches below the ground surface. Tree roots can help in the purification process that occurs underground; however, aggressive roots that disrupt or clog the pipes will damage the field. Avoid poplars and willows. Cherries, dogwoods, hemlock, crabapples, oaks, sourwood and pine trees are better choices for planting near leach fields.

Space out trees so they are between the pipes if possible. Drainage trenches are typically 3 feet wide and have 6 feet of regular soil between them.

Plan to put the trees as far from the leach field as possible if you are still concerned about the root system. Estimate the spread of the roots upon maturity. The expected height of the tree will tell you the spread of the roots. So, a 30-foot-tall tree should be at least 30 feet from the leach field.

Work the soil to loosen it up before planting. Roots will grow until they find a crack. That crack may be the leach field piping. Make the planting hole as wide as possible and loosen the soil on the side of the tree facing away from the septic system. This will encourage roots to spread in the opposite direction of the leach field. Add organic matter like compost if the soil is poor.

Install a root barrier between the leach field and trees. Geotextiles that contain an herbicide are successful at restricting root growth. Dig a trench at least 3 feet from the leach field. Install the barrier so it extends from ground level to a depth of at least 2 feet. It should run the entire length of the leach field. The trees should be at least 5 feet away from the barrier.