When Elaeagnus are used as nurse trees for timber crops, they are usually planted in alternate rows with the main species. Because of their short stature and slower growth, they usually do not compete significantly with the main crop. Root nodules are common and numerous on all species of Elaeagnus growing in moist soils. On semiarid sites, modulation is limited in upper soil layers but nodules will likely form well below the soil surface where moisture is available on a continuous basis. Root nodules are formed by direct penetration of young roots by the actinomycete bacterium Frankia .
Root nodules are perennial and increase in size as the tree continues to grow.
Young active nodules are snow-white in surface coloration, although older interior parts of nodules are light or dark brown and woody. Elaeagnus is modulated by Frankia strains that also nodulate Hippophae and Shepherdia , but not by strains that colonize other actinorhizal plants such as Casuarina and Alnus . Unlike Rhizobium , Frankia survive in the soil for long period without the presence of host plants. However, if Elaeagnus is to be used for reclaiming severely degraded soils or mine sites, it is appropriate to inoculate in the nursery. Estimates of nitrogen fixation by Elaeagnus species have not been carefully made, but it probably does not fix as much nitrogen as other actinorhizal species like Alnus or Casuarina .