In a 2-yr field study, selective application of a 2.5% (v/v) solution of the ammonium salt of fosamine [ethyl hydrogen(aminocarbonyl)phosphonate] plus 0.5% (v/v) nonionic surfactant to multiflora rose (Rosa multiflora Thunb. # ROSMU) demonstrated leaves to be the major site of uptake for suppressing growth. In greenhouse studies, 14C-fosamine was absorbed in decreasing order by axillary bud, leaf, and stem treatments, respectively. 14C was rapidly translocated throughout multiflora rose plants when applied to leaf, stem, or bud tissue. The highest 14C concentration always occurred at the site of uptake. In a 32-day study, the treated leaf, the treated bud, and treated stem had the highest 14C concentration when 14C-fosamine was leaf, bud, or stem applied, respectively.