This research determined the agricultural properties of pyrrhotite-rich exposed tailings of a Ni-Cu Mine, at Thompson, Manitoba, the state of plants colonizing them, and did greenhouse tests of standard revegetation techniques. Top- and sub-soils of the tailings were compared with glaciated clay soils in a Control Area. The most important characteristics of the Exposed Tailings are low Net Neutralization Potential (-1.27 to -243.67 kg CaCO₃ eq./tonne) and high salinity (2.58 to 19.0 dS/m) in the root zone. The tailings and the plants growing on them contain high Ni. In the greenhouse experiment, plant growth was suppressed even though tailings were neutralized and treated with organic matter and fertilizer. Therefore, the standard revegetation methods can not be applied. We recommend a protective layer of waste rock fines to limit root growth into the tailings. This layer should be covered by organic layer for plant growth. The protective layer would also decrease the production of windborne dust and the flow of oxygen into the tailings.