Abstract: A method of maintaining vegetation above frost damage levels in which the roots, stems, trunks or foliage of the vegetation is surrounded by a phase change material having a melting point in excess of the frost damage level, which phase change material is encased in a plurality of bags or in an elongated tubular member. In the case of use of an elongated tubular member, it may be coiled directly about the vegetation or coiled in stacks positioned above the vegetation or laid below ground in rows or coiled within the interior of an automotive tire proximate the vegetation which serves to directly collect solar energy. A fluid path is provided through the center of the tubular member which is coupled to a solar collector. The solar thermal energy collected thereby is transfered via fluid recirculating in this path to the phase change material such that the phase change material melts.