Styrofoam cones for winter protection
I'm not sure if I read about winter protection in this listserver or the Zingiber listserver. Somewhere, I heard of some Styrofoam-like material that was cone shaped and was placed over a tender plant to add winter protection. Reportedly it added a zone or 2 of winter tolerance.
I've looked in the local Home Depot, local Hardware store, a couple nurseries and have even called a plastic pot wholesaler but can't come up with any information.
Does anyone have any experience with these and if so, does anyone know of a supplier so that I can get the local nursery to purchase a mass of them?