How can plants affect my plumbing?
The major issue with regard to plumbing is root infiltration of the sewer line. When pipes are laid underground, the soil around them has typically been dug out and loosely backfilled. It’s much easier to establish roots in loose soil than compacted, so trees will take advantage of such areas if they’re available. Roots are also incredibly tenacious in their hunt for water and nutrients, and your home’s sewer lateral (the pipe running from the house to the public sewer main) just happens to contain plenty of both.
Once roots find their way in – usually by way of a loose joint in the lateral pipe – the feeding frenzy begins. They continue to grow and travel, compounding their own obstruction by capturing oil and grease, debris and bathroom waste. And blockages might only be the beginning; given a point of entry, even just a crack, tree roots can break through boulders. So a pipe made of PVC, concrete, or clay doesn’t really stand a chance. How can you avoid this scenario? You’ll need to do your homework.
What can I do to prevent root infiltration and other problems?
It’s important to know the lay of the land before you break out the shovel. The primary concern is the lateral, but the ground around your home is concealing a network of other pipes and cables, too. Knowing the location of these is key to a successful planting. Your city’s public works department should be able to provide you with this information, or you can call 811 (http://www.call811.com) a few days ahead to have utility companies mark the relevant lines in your yard for free.
Once you know what and where to avoid, you’ll have either the simple matter of finding a good spot, or an intractable dilemma. It all depends on the location of the lateral, the size of the yard, and the type of tree or plant you want. It could be that the “perfect” spot in your yard – the one you stare at every day through the window, the one that needs a tree – is the absolute worst place you could ever plant. Just try to keep in mind the problems it could lead to down the road: not only is there the shame of neglecting good advice, but a torn-up yard, and a massive bill as well.
Among your available planting areas, you’ll obviously want a location with enough water and nutrients for the tree you’ve chosen. These requirements vary by the tree, and you’ll want to get specific on how to keep it happy. It may be helpful to break up and amend some soil around the planting area and away from pipes to encourage root growth in that direction. Remember that roots, like most things, take the path of least resistance whenever possible.
Though it varies with the type of tree, a good rule of thumb for planting distance is to take the height of the mature tree and add 20%. This may not always be practical, so some go with the height alone. Still others maintain that a mere 10 feet from the sewer line is acceptable. We believe the further, the better. If you’re on a septic system, avoid planting above the tank or the leach field. Instead, try to find a spot near the end of the line. If you really need to plant something on the field, go small and try to plant between the drain lines.
Read more about root infiltration at PlumbingSupply.com