How the Wrong Landscaping Can Damage Your Plumbing

By Alexia Jones

Trees, flowers, and shrubbery brighten up the outside of your home. But landscaping can wreak havoc on plumbing if greenery grows too close to the house. Sewer lines, pipes, hoses, and septic systems are prone to damage from spreading tree roots and groundcovers.

Clogged Pipes

Plants need water and nutrients to grow – they get their food from the soil in your yard.  Growing roots spread underground. Roots meet up with the house’s plumbing, but they don’t stop growing. Instead, they wrap around, push through, and ultimately clog and damage the drainpipes. 

Sewer Lines and Leaks

In cities and municipalities, sewers connected from houses to main lines are called “laterals.” Lines filled with water attract tree roots searching for moisture. Shifting soil and frost can crack sewer lines, making them vulnerable to roots that exert strong pressure.  They can move into concrete, plastic, iron, and other materials.  Roots are able to become strong enough to crush sewer line pipes.

One of the most expensive fix-it projects for homeowners involves a leaking sewer.

Understanding the sewer system in your home — where it is and how it connects to municipal works — is important.  Do NOT plant trees, shrubs, groundcover, and flower beds too close to sewer systems.  Clay, plastic or terra cotta pipes are more susceptible than copper ones, but they all are prone to damage.   

Roots that enter the sewer lines thrive on the water and wastewater nutrients – they grow into a dense mat of vegetation. The clump blocks the sewage line, which may stop the flow of waste from toilets. If the waste cannot flow through, you’re bound to have a backup into the house.

Yuck!  At that point, your best bet is to call a plumber.

Septic Systems

Homes with septic systems or leaching fields also need to be kept root-free. Tree and shrub roots grow through drain fields to drink up nutrients from the wastewater. Roots entangle and then choke the tank, keeping it from draining properly. Septic systems need to drain in fields, which becomes difficult among a mass of growing, tangled roots. 

Don’t let the presence of the septic tank deter you from any planting, though. You want some shallow-rooted plants over the tank to absorb excess water and prevent erosion. But choose carefully. Grasses put down roots only a few inches, and are good choices. If you must landscape, choose species of bushes and trees that put down shallow roots

Prevention

Depending on the variety, healthy tree roots are going to spread underground. But chemicals such as copper sulfate and potassium hydroxide can prevent roots from getting into the pipes and septic system. You can also bury metal and wood barriers to block roots … to some extent. Metal and plastic screens are available at your local hardware store. 

If you’re planting a new garden, flowerbeds, or trees on the property, determine where the pipes and sewage lines are beforehand. It only takes one slash from a shovel to break a water line. Main water pipes are typically buried in a straight path from the water meter to the house, but irrigation lines may be in many areas of the yard. Sewage system lines are placed nearer to the street or a septic system. 

Lawn and Yard Prep

Seasonal landscape maintenance helps keep unwanted vegetation from spreading to the pipelines. When planting new greenery near utility lines, avoid birch, willows, oaks, holly. and ivy — they have far-reaching root systems.  

Slow-growing trees with small root balls are a better choice for yards. Think Japanese maple, dogwoods, crabapple, and winter king hawthorn.

Check with a professional landscaper — and a plumber — to determine the best trees for your yard. 

You can also dress up your property by hardscaping with rocks, edging, trellises, fencing, and waterfalls. Built-in ceramic planters, stone pathways, tiled steps, gazebos, pergolas, and retaining walls lessen the need for big trees. Small shrubs are a better option for underground pipes. 

When it comes to landscaping, it’s easy to pick out the most eye-catching trees, flowers, and shrubs, and that’s OK. But planting them in the wrong place could be a costly mistake.


Alexia Jones owns a landscaping company whose services include repairing and winterizing sprinkler systems. She is an expert in sustainable lawns and landscapes and efficient irrigation systems.