"Ground cover" means any herbaceous plant or any woody seedling or shrub generally less than 3 feet in height. The term does not include lawns, landscaped areas, gardens, invasive species as listed by the department of agriculture, markets, and food in accordance with RSA 430:53, III, exotic aquatic species listed pursuant to Env-Wq 1303, imported organic or stone mulches, or other artificial materials.
N.H. Admin. Code § Env-Wt 602.21