Black walnut foliage samples collected from a wide range of sites during a national survey of the New Zealand (NZ) resource conducted in 1979 were analysed for N, P, K, Ca, Mg, B, Fe, Mn, and Zn. Provisional American standards applied to the foliar data indicate that only very small proportions of the field population (individually 1 to 2%) have foliar levels of N, P, Fe, Mn, or Zn rating deficient. For K, Ca, Mg, or B foliar levels consistently exceeded the deficiency threshold. The proportions of the population rating intermediate were very large (40 to 95%) for certain elements (P, Mg, Fe, Zn), and fairly large (16 to 27%) for the remainder. In this transitional bracket response to fertiliser is uncertain. As the applicability of the American criteria to NZ conditions is unproven, this evaluation must remain tentative.