Tree roots can be persistent and aggressive in their mission to attack your pond liner, almost as if it were a personal vendetta! If you have seen sidewalks or even building foundations buckled and destroyed by the inexorable spread of tree roots, the answer here is fairly obvious: Yes, tree roots can and will eventually grow through your pond liner if given a chance. The battle to defend your pond from tree roots may be never ending, but you do have a number of tools on your side to help you keep the roots at bay.
1. The obvious first step is to choose a liner that is naturally resistant to puncture from sharp tree roots. A tightly woven, impermeable liner will hold up much longer than a uniform material such as rubber. Underlayments can help as well, but they allow moisture to pass through, so moisture seeking roots will still be attracted. 2. Choose a site for your pond that is away from existing trees. Digging through tree root systems is difficult, risks injuring the tree itself, and puts your new pond directly in harm’s way, with the enemy literally at the gates. 3. If you want a lovely shaded site for your pond, consider using a tree that’s suited to life in a container. Over time, even containerized roots will begin to expand through their pot’s drainage holes as they seek moisture, but depending on the size of the tree, you may be able to relocate or replace it before the roots become a threat. 4. Consider installing an impermeable root barrier when you plant your trees. Utilities use these regularly, and they’re basically a wall around the root zone that deflect roots to grow in another direction. 5. Choose your tree species carefully if there will be any relatively close by. Do they have shallow, highly invasive roots? Are they moisture seekers that will send rogue shoots to follow the smallest hints of moisture that splash from your water feature? No matter how beautiful, these troublemakers aren’t worth the struggle.
