Do Weeping Willow Trees Harm Plumbing?

Willow Roots

• While it's intriguing and more verbose to say that weeping willow tree roots "hunt" or "seek out" areas for water, it's not an accurate way to describe tree root growth. All trees, including those of the weeping willow, are best described as opportunistic. The shallow roots of a willow spread out quickly in all directions in the soil, absorbing water and nutrients. However, with such a large, expansive matrix, chances are some roots will happen across areas of soil of greater nutrition or water. In the case of the willow tree, once a more opportune soil area is encountered, root growth intensifies and increases to utilize the water or nutrients.

Plumbing Pipes

• Historically, underground water conduits were made of clay, concrete and later metal. All of these materials deteriorate because of contact with moisture and the natural expansion of the soil around them from frost and fluctuations in soil moisture over time. Weeping willows take advantage of any moisture that leaks and dampens the soil. Pores, cracks and chipped breaks in plumping lines or ground drainage systems provide an advantageous water source for the weeping willow as well as any other tree. Today, PVC pipes are used, which are engineered for longevity and do not develop cracks or breaks as easily as older pipe materials.

Concerns

• While an oak or spruce tree can invade moist soils around plumbing just like a weeping willow, the issue is that willow's rapid growth rate more quickly envelops or invades pipes. Roots cannot penetrate through pipes on their own. They need an opening to reach the interior of the pipe. Once a root is able to get inside a pipe, the natural growth and expansion of the root helps enlarge the crack or hole. The water-loving weeping willow roots continue to grow inside the pipe, leading to clogs, reduced water flow or complete blockage.

Advice

• Numerous species and cultivars of weeping willow trees exist, all growing to different mature sizes. If you want a weeping willow, search for one that is not a large, massive tree at maturity. Larger trees develop larger, farther-reaching roots. The safest strategy is to not plant a weeping willow within 30 feet of any plumbing or drainage system on your property. Plant the weeping willow instead on the shore of a pond, in a water-collecting depression or ditch, or in a spacious field or park.