Dawn of the Ditch Lily
I purchased my home in 2008. Since then I have waged a constant war with the prior owner's planting choices. Most notably a huge orange ditch lily that refuses to die. I have tried every thing imaginable to get rid of it but I swear every year it comes back bigger than the year before! I have given up trying to dig it out after finding that any root piece left behind becomes a new plant. Last weekend I did the following:
1) Sprayed Round Up on every single shoot and piece I could find after cutting it. Waited 2 hours and repeated application.
2) Put 2 layers of garbage bags on top to smother it and keep light out.
3) Put half a box of leftover Porcelain tile on top of the garbage bags to further smother.
It's growing, and though it hasn't gone through the bags, it's several raised places high enough to cause the tile to move!! Short of setting it on fire - which I would do if it wasn't right next to he house - what else can I do to destroy this monstrosity?