Board Thread:False Info and Speculative Discussion/@comment-24.130.28.230-20150721180826/@comment-4091815-20160131174537

Nervous is correct. I forgot Meredith and was speaking of the Martins. Her Grandmother built her boathouse from mountain ash and left an urn full of it for Lydia. When tossed to the front of the boathouse, it created a mountain ash barrier.

Only information presented on the show is considered canon. Two different writers in two different episodes were responsible for in information in question. It actually doesn't matter if they were both sloppy. What was said is canon unless they recon it later.