Q. I would like to plant some trees in my yard, but am worried about their invasive roots clogging my sewer line. A neighbor of ours in the old neighborhood had a clogged sewer line and found the roots from a large Silver Maple tree were the problem. Also, it seems that my township forbids planting weeping willows because of this sort of potential problem with clogged sewer lines. Can you suggest any trees that have “well-behaved roots” and are less likely to cause a problem with my sewer line?
A. Tree roots cannot break their way into intact sewer lines — not even weeping willows. The problem occurs when old terra cotta pipes crack or develop leaks at the joints. The roots of almost any tree will take advantage of the situation and could wind up clogging the lines. This is much less of a concern in newer developments because now builders use PVC pipe, which is much less likely to crack and invite an invasion of roots.
Sidewalk damage from tree roots
We used to believe that tree roots were a mirror-image of the top of the tree, but research has shown that tree root systems are much shallower and broader spreading than that.
Smaller trees such as crabapple (Malus spp.), Japanese maple (Acer palmatum) and ‘Winter King’ hawthorn (Crataegus viridis), or large shrubs such as bottlebrush buckeye (Aesculus parviflora), quince (Chaenomeles spp.), and blackhaw viburnum (Viburnum prunifolium) would have less extensive root systems than very large trees such as Norway, silver or sugar maples (Acer spp.), willows (Salix spp.) or oaks (Quercus spp.). Willows and Silver Maples are sometimes called ‘water seekers.’
Weeping Willows are often called ‘water seekers’
You should be more concerned about doing a thorough assessment of your planting site so you can chose trees that will grow well in those conditions. The factors to consider should include:
Once you have assessed the planting site, then you can narrow the list of possibilities to those tough, durable trees that do not have major insect or disease problems that would require your constant attention to keep your chosen plants healthy.
Weeping tree photos – Real attention getters!