Substrate and Furnishings. As obligate burrowers, Russian tortoises should be provided with a fairly deep layer of appropriate bedding. Reptile (orchid) bark, shredded aspen, clean soil, and cypress mulch are all acceptable choices. The substrate used should be easy to clean, and suitable for digging.ubstrate and Furnishings. As obligate burrowers, Russian tortoises should be provided with a fairly deep layer of appropriate bedding. Reptile (orchid) bark, shredded aspen, clean soil, and cypress mulch are all acceptable choices. The substrate used should be easy to clean, and suitable for digging.