How to Plant Shade Trees Near Septic Tank

Tree's roots can damage septic tanks.

A number of trees can seriously damage a septic tank or clog the drainage field if planted on or near the septic system. However, there are some trees with less aggressive roots that can provide shade if placed at a safe distance away from the septic tank. Trees and shrubs can benefit from the nutrients in the drainage field, but they can also cost you problems in the future. Learn about how to plant shade trees without damaging your septic tank.

Difficulty:

Moderate

Instructions

Things You'll Need

• Shovel Compost Root barrier

1. Choose a nonaggressive rooting tree to plant in your yard such as a Dogwood, Cherry, Crabapple and Oak (red oak, scarlet oak and white oak). Avoid trees that grow longer, woody roots such as the Willow, Poplar, Maple and Pine.

2. Determine where your septic tank is in your yard before doing any digging. Professional plumbers can use a sounding rod to follow the sewer lines to your septic tank as well as measure the drainage field. An alternative is to ask the prior owner of the property if they know where the septic tank is located.

3. Dig a hole for the tree so when its roots mature, it will have enough distance away from the septic tank and drainage field. If the tree you pick will be 40 feet tall, then plant the tree at least 40 feet away from the septic system. Also, the depth of the hole is important, because if you dig too deep, the tree will die. It's best to have about 10 percent of the root ball showing out from the soil.

4. Prepare the soil by digging as wide a hole as you can, and till the soil with organic materials such as grass clippings before planting the tree. Emphasize the area of the hole that is away from the septic tank. Trees will take the path of least resistance, so if their roots find a crack in the soil that leads to your septic tank, you will be in trouble.

5. Install a root barrier at least 5 feet into the soil and at least 3 feet away from the drainage field. Root barriers, which look like panels, contain herbicides that can help create a boundary between the tree's roots and the septic system. By digging into the soil, the panels can be positioned around the tree and then covered with the soil.

Tips & Warnings

• Shallow rooting trees are less likely to affect your septic system.

• It's possible for trees to thrive if they are planted close to a septic system, but there is no telling when the roots will damage your system, which is costly to replace.

Resources

• Guide to Planting Trees Near a Septic System
• Root Barriers